fasteners standards

1

TechnicalHandbook

1

IMPORTANT

Holo-Krome has published this handbook as a guide to dimensional, mechanical, and applicationdata for Holo-Krome Socket Screw Products. However, the following limitations must be carefullyobserved in using the information presented in this handbook:

(1) The data in this handbook is subject to change from time to time as a result of changes inproducts and specifications. To obtain the latest technical data pertaining to Holo-Kromeproducts, contact the Holo-Krome Engineering Department.

(2) Certain products listed in these tables are non-stock products. Specifications of non-stockproducts may differ slightly from the handbook description, due to differences in the manufac-turing process.

(3) Proper screw sizes and tightening torque for any given application is a function of the variousdesign parameters, such as heat, lubrication, etc. Therefore, the data in this handbookshould be used only for general guidance in conjunction with the specific design criteria andwith the application of proper engineering principles.

(4) Holo-Krome disclaims all responsibility for its products if they are modified in any way, includ-ing plating, hardness alterations, drilling, etc. Specials will be quoted complete by Holo-Krome on request.

(5) Appropriate specifications are shown with the applicable products. Many of these are writtenby consensus organizations, and, while Holo-Krome intends that its standard products meetthese specifications in all respects, there are changes which take place over the years andmust be considered not applicable on a retroactive basis.

(6) This handbook has been revised to provide data for Metric module products as well as thosein Inch module. The organization of the book is designed to make it easy for the user to findhis information in whatever module he is working. The Dimensional Data in each case ispresented for the various products, followed by the Application Data. Inch module is pre-sented complete, followed by the Metric.

The Holo-Krome Engineering Department welcomes questions regarding fasteners for specificcustomer applications. Their technical experience and special test facilities in the precision fas-teners field are available to help solve your fastener problems.

i

2

Quality is frequently defined as conformance tospecification, and at Holo-Krome a great deal of effortis expended in ensuring that the products shipped do,in fact, meet the required specification.From the placing of the raw materialorder, through the shipping andcertification of the finished product,Holo-Krome procedures andspecifications are applied tomeet that objective.

The definition of the required specification requiresa little discussion. Holo-Krome’s products, like those ofany manufacturer, must meet certain criteria. Thedefinition of those criteria can be done several ways. Itis common for people to refer to an “Industry Stan-dard,” when they are looking for an easy way to definea product. Actually, any manufactured article must, ofnecessity, have two sets of characteristics: the dimen-sional, controlling the size and shape, and the me-chanical, controlling the base material and the per-formance of the product. In the fastener industry, thereare many organizations which write standards or

specifications for this product. In thecase of socket head cap screws, forinstance, one set of applicablestandards would be the ASME/ANSIB18.3, which defines the dimensionalcharacteristics of this product, and

ASTM A574, which defines the mechanical properties.Both of these are quite detailed, providing on the onehand, basic size definitions such as diameter, lengthand thread size, as well as surface finish, concentricityand method of manufacture, and, on the other handthe basic chemistry, heat treatment, hardness, tensilestrength and other metallurgical characteristics, as wellas the tests necessary to establish they have beendone correctly.

Holo-Krome’s specification for raw material hasbeen designed to provide material which will properlymake the desired product, without inherent flaws thatmight be harmful. When the material is received, it isinspected to be sure that it does meet those specifica-tions, and then a Lab Number is assigned, which willprovide traceability throughout manufacturing, testing,storage and shipment.

From the first set-up on the first machine, cali-brated gages and control charts are used to ensureconformance to the prints which have been assigned,and at heat treatment, utilizing atmosphere-controlledfurnaces, testing is performed to the further corrobo-rate adherence to specification. In the case of specialproducts, the customer may request other specifica-tions to meet his own particular needs. There aremany specifications in existence for the type of productwe are discussing, and the selection of these specifi-cations is a matter of agreement between purchaserand seller. In most cases, the “Industry Standard” isused, which is the combination shown above, forsocket head cap screws.

The ingredient necessary to provide all of theseassurances lies in Holo-Krome’s people, who aretrained in the various arts and skills needed to performthe checks and tests required. In addition to thesepeople and their skills is the physical plant and equip-ment which they use. From indicating thread gages ofthe latest type, and laser measuring equipment, toautomated devices to create metallographic speci-mens, as well as appropriate testing equipment, theinvestment has been made to have available whateveris required for assurance that the specifications arebeing met.

This devotion to qualityis a company philosophy,from top management tothe last packer on the line.Quality is everybody’s job,and every associate in theHolo-Krome organization isaware of that fact, and verymuch a part of it. AssociateInvolvement Groups areused in the plant to helpsolve problems which arebroader in scope than asingle machine, and thesehave proven to be success-ful in the drive for continu-ous improvement which isthe Holo-Krome philosophy.

THE HOLO-KROME QUALITY STORY

ii

3

INCH FASTENERS

III

4IV

TABLE OF CONTENTSDIMENSIONAL DATA Page No.

Socket Head Cap Screws-1960 Series ................................................................................................................... 1-6Sems for Socket Head Cap Screws ........................................................................................................................ 7-8Low Head Cap Screws............................................................................................................................................ 9Flat Countersunk Head Cap Screws ....................................................................................................................... 10,11Button Head Cap Screws ........................................................................................................................................ 12Hexagon and Spline Sockets .................................................................................................................................. 13Socket Head Shoulder Screws ............................................................................................................................... 14,15Set Screws .............................................................................................................................................................. 16-18Dowel Pins and Pull Dowel Pins ............................................................................................................................. 19Allen Wrenches and Bits ......................................................................................................................................... 20Allen Spline Keys and Bits ...................................................................................................................................... 21Socket Pressure Plugs-Dryseal-(NPTF)-3/4 Taper ................................................................................................. 22Socket Pressure Plugs-Flush-(PTF)-7/8 Taper ....................................................................................................... 23Socket Jam Screws................................................................................................................................................. 24Allenuts ................................................................................................................................................................... 24Holo-Krome Thread Standards and Radius Root Dimensions................................................................................ 25Holo-Krome Finishes............................................................................................................................................... 26Galvanic Corrosion.................................................................................................................................................. 26Thermal Expansion ................................................................................................................................................. 26

MECHANICAL PROPERTIES AND APPLICATIONS DATA .................................................................................. 27

Mechanical Properties and Applications Data......................................................................................................... 28Comparison-Socket Screws and Hex Head Screws ............................................................................................... 29Applications of Various Head Styles ....................................................................................................................... 30Mechanical Properties-Socket Head Cap Screws-1960 Series .............................................................................. 31Torque Data-Socket Head Cap Screws-1960 Series .............................................................................................. 32Decarburization and Discontinuity Limits ................................................................................................................ 33Mechanical Properties-Stainless Steel Socket Head Cap Screws.......................................................................... 34Mechanical Properties-Button Head, Flat Countersunk Head, Low Head Cap Screws .......................................... 35Tightening Torque-Button Head, Flat Countersunk Head, Low Head Cap Screws ................................................ 35Mechanical Properties-Socket Shoulder Screws .................................................................................................... 36Socket Set Screws-Alloy Steel-Application Data .................................................................................................... 37Socket Set Screws-Axial Holding Power ................................................................................................................. 38,39Mechanical Properties-Allen Wrenches and Bits .................................................................................................... 40Application Data-Socket Pressure Plugs ................................................................................................................ 41Coated Pressure Plugs ........................................................................................................................................... 42Mechanical Properties-Dowel Pins ......................................................................................................................... 43Holo-Krome Nylok Hex-Socket Screws................................................................................................................... 44,45Fastener Related Standards ................................................................................................................................... 46,47General Application Data-Index .............................................................................................................................. 48Glossary of Terms ................................................................................................................................................... 49,50Tapping Hints .......................................................................................................................................................... 51Tap Drill/Hole Sizes................................................................................................................................................. 51Fastener Joint Design ............................................................................................................................................. 52Fastener Strengths.................................................................................................................................................. 53Metric Conversions ................................................................................................................................................. 54Hardness Value Conversions.................................................................................................................................. 55Effects of Alloying Elements.................................................................................................................................... 56Metric Socket Fasteners ......................................................................................................................................... 57

5

Inch SectionINDEX TO TABLES

Page No.Table 1 Holo-Krome Socket Head Cap Screws-Dimensions 1960 series ..................................................... 1Table 1A Dimensions of Underhead Fillets ..................................................................................................... 2Table 2 Holo-Krome Socket Head Cap Screws- Body and Grip Lengths ..................................................... 3Table 3 Holo-Krome Socket Head Cap Screws-Functional Limits for

Runout of Head, Body and Thread ................................................................................................... 4Table 4 Dimensions for Drilled-Head Socket Screws .................................................................................... 5Table 5 Drill and Counterbore Sizes - Socket Head Cap Screws-1960 Series ............................................. 6Table 6 Dimensions of Helical Spring Lock Washers for Socket Head Cap Screw Sems ............................ 7Table 6A Dimensions of Plain Washers for Sems ........................................................................................... 8Table 6B Dimensions of Conical Spring Washers for Sems ............................................................................ 8Table 7 Holo-Krome Socket Low Head Cap Screws-Dimensions ................................................................. 9Table 8 Holo-Krome Socket Flat Countersunk Head Cap Screws-Dimensions ............................................ 10Table 9 Holo-Krome Socket Flat Countersunk Head Cap Screws-Body and Grip Lengths .......................... 11Table 9A Holo-Krome Socket Flat Countersunk Head Cap Screws-(Beyond sizes in Table 9) ..................... 11Table 10 Holo-Krome Socket Button Head Cap Screws-Dimensions ............................................................. 12Table 11 Holo-Krome Hexagon and Spline Sockets-Dimensions ................................................................... 13Table 12 Holo-Krome Socket Head Shoulder Screws-Dimensions ................................................................ 14Table 13 Holo-Krome Socket Set Screws-Dimensions ................................................................................... 16,17Table 14 Holo-Krome Socket Set Screws-Key Engagements for Short Length Set Screws .......................... 18Table 15 Holo-Krome Dowel Pins-Dimensions ............................................................................................... 19Table 16 Holo-Krome Pull Dowel Pins-Dimensions ........................................................................................ 19Table 17 Allen Wrenches and Bits-Dimensions .............................................................................................. 20Table 18 Allen Spline Keys and Bits-Dimensions ........................................................................................... 21Table 19 Holo-Krome Socket Pressure Plugs-Dryseal (NPTF) Type-3/4 Taper-Dimensions ......................... 22Table 20 Holo-Krome Socket Pressure Plugs-Flush (PTF) Type-7/8 Taper-Dimensions ............................... 23Table 21 Holo-Krome Socket Jam Screws-Dimensions .................................................................................. 24Table 22 Allenuts-Dimensions ......................................................................................................................... 24Table 23 Holo-Krome Thread Standards ........................................................................................................ 25Table 24 Holo-Krome Finishes ........................................................................................................................ 26Table 24A Galvanic Corrosion ........................................................................................................................... 26Table 24B Thermal Expansion .......................................................................................................................... 26Table 25 Holo-Krome Socket Head Cap Screws Series Mechanical Properties-1960 Series ........................ 31Table 26 Holo-Krome Socket Head Cap Screws-Torque Data-1960 Series ................................................... 32Table 27 Decarburization and Discontinuity Limits ......................................................................................... 33Table 28 Holo-Krome Stainless Steel Socket Head Cap Screws ................................................................... 34Table 29 Holo-Krome Button, Flat Countersunk Cap Screws-Mechanical Properties & Tightening Torque ... 35Table 29A Holo-Krome Low Head Socket Cap Screws-Mechanical Properties & Tightening Torque .............. 35Table 30 Holo-Krome Socket Shoulder Screws-Mechanical Properties ......................................................... 36Table 31 Holo-Krome Socket Set Screws-Axial Holding Power ...................................................................... 38Table 32 Holo-Krome Allen Wrenches and Bits-Mechanical Properties & Application Data ........................... 40Table 33 Holo-Krome Pressure Plugs-Application Data ................................................................................. 41Table 34 Holo-Krome Dowel Pins-Mechanical Properties .............................................................................. 43Table 35 Fastener Related Standards ............................................................................................................ 46,47Table A-1 Common Tap Drill Sizes-Inch & Metric ............................................................................................ 51Table A-2 Fastener Strengths ........................................................................................................................... 53Table A-3 Conversion Table-Fractional Inch to Decimal Inch and Millimeter ................................................... 54Table A-4 Conversion Table-Millimeters to Inches ........................................................................................... 54Table A-5 Decimal Equivalents-Drill Sizes ........................................................................................................ 54Table A-6 Hardness Value Conversions ........................................................................................................... 55

V

6

Intentionally Left Blank

7

1/165/645/64

3/323/327/649/64

5/323/161/45/16

3/83/81/25/8

3/43/47/87/8

111-1/41-1/2

HEXAGONSOCKET

SIZE

0.0620.0780.078

0.0940.0940.1090.141

0.1560.1880.2500.312

0.3750.3750.5000.625

0.7500.7500.8750.875

1.0001.0001.2501.500

0.050

LENGTH TOLERANCES, L

NOMINAL SCREW SIZE

TOLERANCE ON LENGTH

Up to 1., Incl.Over 1 in. to 2-1/2, Incl.Over 2-1/2 to 6, Incl.Over 6

-0.03-0.04-0.06-0.12

-0.03-0.06-0.08-0.12

-0.05-0.10-0.14-0.20

--0.18-0.20-0.24

HOLO-KROMETHERMO-FORGED®

GRAIN FLOW

NOMINALSCREW LENGTH

7/16,Thru3/4,,Incl.

Over1-1/2

7/8,Thru1-1/2,Incl.

0Thru3/8,Incl.

SPLINESOCKET

SIZE

0.0600.0720.0960.096

0.1110.1110.1330.168

0.1830.2160.2910.372

0.4540.4540.5950.620

0.6980.790

--

----

HEADSIDE

HEIGHT

0.0910.1120.1340.154

0.1760.1980.2180.262

0.3030.3650.4570.550

0.6420.7350.9211.107

1.2931.4791.6651.852

2.0382.2242.5972.970

0.0960.1180.1400.161

0.1830.2050.2260.270

0.3120.3750.4690.562

0.6560.7500.9381.125

1.3121.5001.6881.875

2.0622.2502.6253.000

0123

4568

101/45/163/8

7/161/25/83/4

7/811-1/81-1/4

1-3/81-1/21-3/42

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.00001.12501.2500

1.37501.50001.75002.0000

NOTES FOR TABLE 1

1. LENGTH. The length of the screw is the distance measured on a lineparallel to the axis, from the plane of the bearing surface under the headto the plane of the flat of the point. It includes the threads and body. Thebasic length dimension on the product shall be the nominal lengthexpressed as a two-place decimal.

Balance of notes on page 2.

STANDARD LENGTH INCREMENTS, L

0 to1 inchIncl.

Over1 inch

1/8 thru 1/41/4 thru 11 thru 3-1/23-1/2 thru 77 thru 10

1/161/81/41/21

1 thru 77 thru 10Over 10

1/212

NOMINALSCREW SIZE

NOMINALSCREW LENGTH

STANDARD LENGTHINCREMENT

TABLE 1 HOLO-KROME SOCKET HEAD CAP SCREWS–1960 SERIES

TABLE 1 DIMENSIONS–1960 SERIES

MAX. MIN.

D(3) A(4)

MAX. MIN.

H

MAX. MIN.

S M(5) J(5)

MIN. NOM. NOM.

T G K LT(2)

MIN. MIN. MAX. MAX. MIN.

THREADLENGTH

KEYENGAGE-

MENT

WALLTHICK-NESS

CHAMFEROR

RADIUS

0.0030.0030.0030.003

0.0050.0050.0050.005

0.0050.0080.0080.008

0.0100.0100.0100.010

0.0150.0150.0150.015

0.0150.0150.0150.015

0.0200.0250.0290.034

0.0380.0430.0470.056

0.0650.0950.1190.143

0.1660.1900.2380.285

0.3330.3800.4280.475

0.5230.5700.6650.760

0.0250.0310.0380.044

0.0510.0570.0640.077

0.0900.1200.1510.182

0.2130.2450.3070.370

0.4320.4950.5570.620

0.6820.7450.8700.995

0.0540.0660.0770.089

0.1010.1120.1240.148

0.1710.2250.2810.337

0.3940.4500.5620.675

0.7870.9001.0121.125

1.2371.3501.5751.800

0.0570.0700.0830.095

0.1080.1210.1340.159

0.1850.2440.3060.368

0.4300.4920.6160.740

0.8640.9881.1111.236

1.3601.4851.7341.983

0.0600.0730.0860.099

0.1120.1250.1380.164

0.1900.2500.3120.375

0.4380.5000.6250.750

0.8751.0001.1251.250

1.3751.5001.750

0.05680.06950.08220.0949

0.10750.12020.13290.1585

0.18400.24350.30530.3678

0.42940.49190.61630.7406

0.86470.98861.10861.2336

1.35681.48181.72951.9780

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.00001.12501.2500

1.37501.50001.75002.0000

0.500.620.620.62

0.750.750.750.88

0.881.001.121.25

1.381.501.752.00

2.252.502.813.12

3.443.754.385.00

0.620.770.800.83

0.991.001.051.19

1.271.501.711.94

2.172.382.823.25

3.694.124.655.09

5.656.087.138.11

1

HEADHEIGHT

HEADDIAMETER

BODYDIAMETER

NOMINAL

SIZE

BASIC

SCREW

DIAMETER

8

2. THREAD LENGTH. LT Thread length of the screw is the distance fromthe extreme point to the last complete or full form thread. See page 3 forgrip and body lengths of standard length screws. LTmax. in Table 1 refersto longer than standard length screws.

3. BODY. LB The unthreaded cylindrical portion of the shank for screwsthat are not threaded to the head.

4. HEAD DIAMETER. Heads may be made plain or knurled at Holo-Krome's option unless specified on the order. For knurled screws, themaximum head diameter includes the knurling. Minimum head diameteris the diameter of the head before knurling, or any unknurled section orband on the head.

HEAD CONCENTRICITY. The heads of Holo-Krome Cap Screws areconcentric with the shank within 1% of the basic screw diameter, Dmaximum (2% total runout), or 0.006 inch total runout, whichever isgreater, when held within one diameter of the head but beyond the fillet.

5. SOCKET CONCENTRICITY. Holo-Krome Sockets are concentric withthe shanks of the cap screws within 1-1/2% of the basic screw diameter,D maximum, (3% total runout), or 0.005 inch, whichever is greater forscrews through a nominal size of 1/2 inch. Sizes above 1/2 inch havesockets concentric with the shank within 3% of the basic screw diameter,D maximum, (6% total runout). See page 13 for socket tolerances.

6. BEARING SURFACE. The plane of the bearing surface is perpendicu-lar to the axis of the screw within a maximum deviation of 1 degree.

7. THREADS AND GAGING. Threads are Unified Standard radius root.On screws with a nominal size 0 through 1 inch inclusive, threads areClass 3A in both UNRC and UNRF. On nominal sizes over 1 inch, threadsare made to Class 2A in both UNRC or UNRF. Holo-Krome screw threadshave controlled radius roots and radiused runout for greater fatigue life.Acceptability of screw threads shall be based on System 22 of ANSI/ASME B1.3M.

Class 3A threads do not provide a plating allowance. When plating isrequired, it is recommended that Holo-Krome supply the parts plated.

8. SCREW POINT CHAMFER. The point shall be flat or slightly concaveand chamfered. The plane of the point shall be approximately normal tothe axis of the screw. The chamfer shall extend slightly below the root ofthe thread and the edge between the flat and chamfer may be slightlyrounded. The included angle of the point should be approximately 90degrees. Chamfering of screw sizes up to and including size 8 (0.164 in.)shall be optional.

9. FILLET. For all lengths of screws the form of the underhead fillet shallbe optional, as depicted in Figure 1, provided it is a smooth and continuousconcave curve fairing into the bearing surface of the head and the screwshank within the envelope established by the limits for fillet extension,length and juncture radius specified in Table 1A.

10. TOTAL RUNOUT. The total runout between the head, body andthreads of socket cap screws shall be such that the screw will assembleinto a compound hole that is threaded at one end to the basic thread size(Class 3B min.) for a depth equivalent to 1.5 times the basic screwdiameter and drilled and counterbored as shown in Table 3. Thesediameters shall be concentric with the axis of the thread within 10% of thethread pitch diameter tolerance. The starting thread shall be chamferedand the corners shall be chamfered or rounded to a diameter equal to Fmax. Table 1A.

Applicable Standards and SpecificationsASME/ANSI B18.3 and ASTM A574

TABLE 1A DIMENSIONS OF UNDERHEAD FILLETS

0123

4568

101/45/163/8

7/161/25/83/4

7/811-1/81-1/4

1-3/81-1/21-3/42

SUPERSEDED DIMENSIONS — 1936 SERIESThe following table is included for reference only.

HEXAGONSOCKET

SIZEHEAD

DIAMETER

MAX. NOM.

0123

4568

101/45/16

————

————

——

7/16

—0.0501/16—

5/64—

3/321/8

——

7/32

HEXAGONSOCKET

SIZE

MAX.

3/87/161/25/8

3/47/811-1/8

1-1/41-3/81-1/2

—5/8—7/8

11-1/81-5/161-1/2

1-3/41-7/8

2

—5/16——

9/169/165/83/4

3/43/4—

NOM.

HEADDIAMETERNOMINAL

SIZENOMINAL

SIZE

NOTES FOR TABLE 1 CONTINUED

FIGURE 1 UNDERHEAD FILLET DETAIL

2

B

MAX.

0.0740.0870.1020.115

0.1300.1950.1580.188

0.2180.2780.3470.415

0.4940.5520.6890.828

0.9631.1001.2351.370

1.5051.6401.9102.180

R E

FILLETLENGTH

0.0120.0120.0140.014

0.0150.0170.0170.020

0.0240.0240.0290.034

0.0390.0440.0540.066

0.0750.0850.0940.102

0.1100.1190.1360.153

MAX.

0.0020.0030.0030.004

0.0040.0050.0050.006

0.0060.0070.0090.012

0.0140.0160.0210.025

0.0310.0340.0390.044

0.0480.0520.0620.071

MIN.

JUNCTURERADIUS

TRANSITIONDIAMETER

NOMINALSCREW

SIZE

9

NOMINALSIZE

1/4 3/8 7/16 1/2 5/8 3/4 7/8 1.000

LG

LB

LG

LB

LG

LB

LG

LB

LG

LB

LG

LB

LG

LB

LG

LB LG

LB

5/16

1-1/21-3/422-1/4

2-1/22-3/433-1/4

3-1/23-3/444-1/4

4-1/24-3/455-1/4

5-1/25-3/466-1/4

6-1/26-3/477-1/4

7-1/27-3/488-1/2

99-1/21011

12131415

16171819

20

.50

.501.001.00

1.501.502.002.00

2.502.503.003.00

3.503.504.00—

————

————

————

————

————

————

—

.25

.25

.75

.75

1.251.251.751.75

2.252.252.752.75

3.253.253.75—

————

————

————

————

————

————

—

.62

.621.12

1.121.621.622.12

2.122.622.623.12

3.123.623.624.12

4.124.624.625.12

————

————

————

————

————

—

.35

.35

.85

.851.351.351.85

1.852.352.352.85

2.853.353.353.85

3.854.354.354.85

————

————

————

————

————

—

.50

.501.00

1.001.501.502.00

2.002.502.503.00

3.003.503.504.00

4.004.504.505.00

5.005.505.506.00

6.00———

————

————

————

—

.62

.62

1.121.121.621.62

2.122.122.622.62

3.123.123.623.62

4.124.124.624.62

5.125.125.625.62

6.126.126.627.12

7.62———

————

————

—

.19

.19

.69

.691.191.191.69

1.692.192.192.69

2.693.193.193.69

3.694.194.194.69

4.695.195.195.69

5.69———

————

————

————

—

.27

.27

.77

.771.271.27

1.771.772.272.27

2.772.773.273.27

3.773.774.274.27

4.774.775.275.27

5.775.776.276.77

7.27———

————

————

—

.75

.75

.751.501.50

1.502.252.252.25

3.003.003.003.75

3.753.754.504.50

4.505.255.255.25

6.006.006.007.00

7.008.008.00—

————

————

—

.36

.36

.361.121.12

1.121.861.861.86

2.622.622.623.36

3.363.364.124.12

4.124.864.864.86

5.625.625.626.62

6.627.627.62—

————

————

—

.75

.75

.751.50

1.501.502.252.25

2.253.003.003.00

3.753.753.754.50

4.504.505.255.25

5.256.006.006.75

6.757.757.759.25

10.25———

————

—

.30

.30

.301.04

1.041.041.801.80

1.802.542.542.54

3.303.303.304.04

4.044.044.804.80

4.805.545.546.30

6.307.307.308.80

9.80———

————

—

1.001.00

1.001.002.002.00

2.002.003.003.00

3.003.004.004.00

4.004.005.005.00

5.005.006.006.00

7.007.008.009.00

10.0011.0012.0013.00

————

—

.50

.50

.50

.501.501.50

1.501.502.502.50

2.502.503.503.50

3.503.504.504.50

4.504.505.505.50

6.506.507.508.50

9.5010.5011.5012.50

————

—

1.00

1.001.001.002.00

2.002.002.003.00

3.003.003.004.00

4.004.004.005.00

5.005.005.006.00

6.007.007.008.00

9.0010.0011.0012.00

13.0014.0015.00

—

—

.44

.44

.44

.441.44

1.441.441.442.44

2.442.442.443.44

3.443.443.444.44

4.444.444.445.44

5.446.446.447.44

8.449.4410.4411.44

12.4413.4414.44

—

—

1.001.001.001.00

2.002.002.002.00

3.003.003.003.00

4.004.004.004.00

5.005.005.006.00

6.007.007.008.00

9.0010.0011.0012.00

13.0014.0015.0016.00

17.00

.38

.38

.38

.38

1.381.381.381.38

2.382.382.382.38

3.383.383.383.38

4.384.384.385.38

5.386.386.387.38

8.389.3810.3811.38

12.3813.3814.3815.38

16.38

For longer lengths or diameters over 1" see Page 1 LT, Table 1

TABLE 2 BODY AND GRIP LENGTHS - 1960 SERIES - LENGTHS ABOVE LINE ARE THREADED TO THE HEAD

NOMINALLENGTH

NOMINALSIZE

0 1 2 3 4 5 6 8 10

LG LB LG LB LG LB LG LB LG LB LG LB LG LB LGL

B LG LB

.25

.25

.50

.75

————

————

———

.19

.19

.44

.69

————

————

———

.25

.25

.62

.88———

————

———

.17

.17

.55

.80———

————

———

.25

.25

.62

.881.12——

————

———

.16

.16

.54

.791.04——

————

———

.25

.25

.62

.881.121.38—

————

———

.15

.15

.52

.771.021.27—

————

———

.25

.25

.75

.751.251.25

————

———

.12

.12

.62

.621.121.12

————

———

.25

.25

.75

.751.251.25

1.75———

———

.12

.12

.62

.621.121.12

1.62———

———

.50

.501.001.001.50

1.502.00——

———

.34

.34

.84

.841.34

1.341.84——

———

.38

.38

.88

.881.38

1.381.881.882.38

———

.22

.22

.72

.721.22

1.221.721.722.22

———

.38

.38

.88

.881.38

1.381.881.882.38

2.382.882.88

.17

.17

.67

.671.17

1.171.671.672.17

2.172.672.67

3/47/811-1/4

1-1/21-3/422-1/4

2-1/22-3/433-1/4

3-1/23-3/44

TABLE 2 HOLO-KROME SOCKET HEAD CAP SCREWS - 1960 SERIES

GRIP LENGTH — LG. The maximum distance from the bearing surfaceof the head to the first completed or full form thread. A clamped part thinnerthan LG would not allow the screw to seat.

BODY LENGTH — LB. The minimum length of the unthreaded cylindricalportion of the shank.

NOMINALLENGTH

3

4

1The largest diameter DE and A

E specified for the various screw sizes in TABLE 3 shall apply for any nominal screw longer than that tabulated for the respective nominal screw size.

TABLE 3 HOLO-KROME SOCKET HEAD CAP SCREWS - 1960 SERIES

1-1/8

DE

AE

DE

AE

1-3/4

DE A

EOVER

6121824

061218

TO, INCL. AE

DE

1-1/4

DE

AE

1-3/8 21-1/2

HOLE DIAMETERS FOR SHANK (DE) AND FOR HEAD (A

E)1

AE

DE

1.1401.1551.1701.185

1.7251.7401.7551.770

1.2651.2801.2951.310

1.9151.9301.9451.960

1.3901.4051.4201.435

2.1042.1192.1342.149

1.5151.5301.5451.560

2.2952.3102.3252.340

1.7651.7801.7951.810

2.6752.6902.7052.720

3.0553.0703.0853.100

2.0152.0302.0452.060

DE

AE

5/161/4

DE

AE

DE

AE

3/8 7/16

DE

AE

1/2

DE

AE

5/8

DE

AE

3/4

DE

AE

7/8 1

DE

AE

DE

AEOVER

12346

246810

01234

02468

.255

.260

.265

.270

.275

—————

.386

.391

.396

.401

.406

—————

.317

.322

.326

.331

.337

—————

.480

.485

.489

.494

.500

—————

.379

.383

.387

.391

.400

—————

.574

.578

.582

.586

.595

—————

.441

.445

.449

.453

.462

—————

.669

.673

.676

.680

.690

—————

—————

.507

.514

.521

.525—

—————

.767

.774

.781

.785—

—————

.631

.638

.644

.650—

—————

.956

.963

.969

.975—

—————

.756

.762

.767

.773

.775

—————

1.1461.1521.1571.1631.165

—————

.880

.886

.891

.897

.900

—————

1.3351.3411.3461.3521.355

—————

1.0051.0101.0151.0201.025

TO, INCL.


E)1

—————

1.5251.5301.5351.5401.545

DE

AE

10

DE

AE

DE

AE

2 3

DE

AE

4

DE

AE

5

DE

AE

6

DE

AE

8 10

DE

AE

DE

AEOVER

.063

.065

.068

.070—

—————

—————

—————

.105

.107

.110

.112—

—————

—————

—————

.076

.078

.080

.082

.087

—————

—————

—————

.127

.129

.131

.133

.138

—————

—————

—————

—————

.090

.095

.099

.103—

—————

—————

—————

.150

.155

.159

.163—

—————

—————

—————

.103

.107

.111

.115—

—————

—————

—————

.171

.175

.179

.183—

—————

—————

—————

.116

.120

.123

.127

.131

—————

—————

—————

.193

.197

.200

.204

.208

—————

—————

—————

—————

.130

.136

.140

.146

.150

—————

—————

—————

.216

.222

.226

.232

.236

—————

—————

—————

.143

.148

.153

.158

.163

—————

—————

—————

.237

.242

.247

.252

.257

—————

—————

—————

.168

.173

.178

.183

.189

—————

—————

—————

.280

.285

.290

.295

.301

—————

—————

—————

—————

.324

.329

.335

.341

.346

—————

—————

—————

.196

.201

.207

.213

.215

NOMINAL SIZE

TO, INCL.


E)1

1/41/23/411-1/2

1/211-1/222-1/2

3/41-1/22-1/434

12346

01/41/23/41

01/211-1/22

03/41-1/22-1/43

01234

TABLE 3 FUNCTIONAL LIMITS FOR RUNOUT OF HEAD, BODY AND THREAD — 1960 SERIES

NOMINAL LENGTH

NOMINAL SIZE

NOMINAL LENGTH

NOMINAL LENGTH

NOMINAL SIZE

5

TABLE 4 DIMENSIONS FOR DRILLED-HEAD SOCKET SCREWS

TOP OF HEADTO CENTER OF HOLE

W

DRILLED HOLEDIAMETER

B

HOLE ALIGNMENTPLUG DIAMETER

MAX. MIN.MAX. MIN.

TABLE 4 CROSS DRILLING DIMENSIONS

6 AND SMALLER 8 AND LARGER

0.0250.0250.0250.030

0.0300.0300.0300.051

0.0510.0510.0510.081

0.0810.0810.1040.104

0.1040.104

0.0330.0330.0330.044

0.0440.0440.0440.061

0.0610.0610.0610.091

0.0910.0910.1190.119

0.1190.119

0.0390.0390.0390.050

0.0500.0500.0500.067

0.0670.0670.0670.097

0.0970.0970.1270.127

0.1270.127

0.0260.0300.0350.040

0.0450.0650.0840.103

0.1210.1400.1780.215

0.2530.2900.3280.365

0.4030.440

0.0400.0450.0500.060

0.0650.0850.1040.123

0.1410.1600.1980.235

0.2730.3100.3480.385

0.4230.460

NOMINALSIZE

4568

101/4

5/163/8

7/161/25/83/4

7/81

1 1/81 1/4

1 3/81 1/2

6

NOTES FOR TABLE 5

CLOSE FIT. Normally limited to holes for those lengths of screwsthreaded to the head in assemblies in which (1) only one screw is used,or (2) two or more screws are used and the mating holes are producedat assembly or by matched and coordinated tooling.

NORMAL FIT. Intended for (1) screws of relatively long length or (2)assemblies that involve two or more screws and where the mating holesare produced by conventional tolerancing methods. It provides for themaximum allowable eccentricity of the longest standard screws and forcertain deviations in the parts being fastened, such as deviations in holestraightness; angularity between the axis of the tapped hole and that ofthe hole for the shank; differences in center distances of the matingholes and other deviations.

CHAMFERING. It is considered good practice to chamfer or break theedges of holes that are smaller than B maximum in parts in whichhardness approaches, equals or exceeds the screw hardness. If holesare not chamfered, the heads may not seat properly or the sharp edgesmay deform the fillets on the screws, making them susceptible to fatiguein applications that involve dynamic loading. The chamfers, however,should not be larger than needed to ensure that the heads seat properlyor that the fillet on the screw is not deformed. Normally the chamfersneed not exceed B maximum. Chamfers exceeding these valuesreduce the effective bearing area and introduce the possibility ofindentation when the parts fastened are softer than the screws, or ofbrinnelling of the heads of the screws when the parts are harder than thescrews.

TABLE 5 DRILL AND COUNTERBORE SIZES — 1960 SERIES

NOM. DEC.

BASICSCREW

DIAMETERNOMINAL

SIZE

A

DRILL SIZE FOR HOLE A

CLOSE FIT NORMAL FIT

NOM. DEC.

X C

COUNTERBORESIZE FORHOLE X

0123

4568

101/45/163/8

7/161/25/83/4

7/811-1/41-1/2

1-3/42

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.00001.25001.5000

1.75002.0000

51*46*3/3236*

1/89/6423*15*

5*17/6421/6425/64

29/6433/6441/6449/64

57/641-1/641-9/321-17/32

1-25/322-1/32

0.06700.08100.09370.1065

0.12500.14060.15400.1800

0.20550.26560.32810.3906

0.45310.51560.64060.7656

0.89061.01561.28121.5312

1.78122.0312

49*43*36*31*

29*23*18*10*

2*9/3211/3213/32

15/3217/3221/3225/32

29/321-1/321-5/161-9/16

1-13/162-1/16

0.07300.08900.10650.1200

0.13600.15400.16950.1935

0.22100.28120.34370.4062

0.46870.53120.65620.7812

0.90621.03121.31251.5625

1.81252.0625

1/85/323/167/32

7/321/49/325/16

3/87/1617/325/8

23/3213/1611-3/16

1-3/81-5/822-3/8

2-3/43-1/8

0.0740.0870.1020.115

0.1300.1450.1580.188

0.2180.2780.3460.415

0.4830.5520.6890.828

0.9631.1001.3701.640

1.9102.180

*Wire size drill

TABLE 5 HOLO-KROME SOCKET HEAD CAP SCREWS — 1960 SERIES

TRANSITIONDIAMETER

B MAXIMUMSEE CHAMFERING,

BELOW

7

TABLE 6 DIMENSIONS FOR SEMS

0.0220.0300.0300.040

0.0400.0470.0620.062

0.0780.0940.1090.125

0.1560.188

0.0220.0300.0300.040

0.0400.0470.0470.062

0.0780.0940.1090.125

0.1560.188

MAX. MIN.

0.1190.1470.1610.193

0.2040.2430.2970.354

0.4460.5410.6290.723

0.9041.089

WIDTH THICKNESS

WASHER SECTION

0.08600.09900.11200.1250

0.13800.16400.19000.2500

0.31250.37500.43750.5000

0.62500.7500

0.0750.0860.1010.113

0.1240.1490.1730.230

0.2900.3530.4110.473

0.5920.713

0.0800.0910.1060.118

0.1290.1550.1790.238

0.2980.3610.4200.482

0.6010.722

MAX. MIN.

2345

68101/4

3/163/87/161/2

5/83/4

MAX. MIN.

0.1290.1580.1740.206

0.2170.2570.3110.370

0.4620.5570.6460.740

0.9211.106

Applicable Standards and SpecificationsASME/ANSI B18.13

TABLE 6 DIMENSIONS OF HELICAL SPRING LOCK WASHERS FOR SOCKET HEADCAP SCREW SEMS

SOCKET HEAD CAP SCREWS FOR SEMS

The socket head cap screw component of sems shall conform to the

specifications for cap screws published in American National Standard

ASME/ANSI B18.3 except (1) that the maximum diameter of the

unthreaded shank shall be less than the maximum major diameter of

the thread by an amount sufficient to prevent disassembly of the washer

from the screw; and (2) that on short length screws where unthreaded

length applies, the full form threads shall extend to within two pitches

(threads) of the contacting face of the washer or closer if practicable.

Where required, threads extending closer than two pitches (threads) of

the contacting face of the washer may be negotiated between the

manufacturer and purchaser.

WASHERS FOR SEMS

The washer components of sems shall conform with the dimensions

and specifications given for the various types in this standard. It should

be noted that the washers for sems may differ dimensionally from the

equivalent over-the-thread washers as specified in American National

Standards, ANSI B18.21.1 and ANSI B18.22.1. Except for helical

spring lock washers where the inside diameters are included for

manufacturing purposes, the holes in the sems washers are not

specified in as much as the washers shall be assembled onto the screw

blanks before the threads are rolled. The edge contour of the hole on

the head side of washer and the size relationship between the washer

inside diameter and the diameter of the unthreaded shank on the screw

shall be such that the washer will be retained on the screw after the

threads are rolled but shall not bind on the shank or impinge on the

underhead fillet of the screw before or during tightening of the

assembly.

WASHER OUTSIDEDIAMETER

WASHER INSIDEDIAMETER

NOMINALSIZE

BASICSCREW

DIAMETER

8

TABLE 6B DIMENSIONS OF CONICAL SPRING WASHERS FOR SEMS

BASIC MAX. MIN. MAX . MIN.MAX . MIN.

0.3070.3700.4330.495

0.6200.7430.8680.993

0.3200.3830.4460.515

0.6400.7650.8901.015

0.13800.16400.19000.2500

0.31250.37500.43750.5000

68101/4

5/163/87/161/2

0.0290.0400.0400.050

0.0600.0790.0870.108

0.0230.0330.0330.042

0.0520.0660.0740.094

0.0160.0160.0160.024

0.0260.0250.0280.031

0.0100.0100.0100.014

0.0160.0150.0180.021

BASIC MAX . MIN. MAX . MIN.

TABLE 6A DIMENSIONS FOR SEMS

WASHER OUTSIDEDIAMETER

TYPE L WASHER TYPE H WASHER

THICKNESS CROWN HEIGHT THICKNESS CROWN HEIGHT

0.0100.0100.0110.011

0.0160.0140.0160.020

0.0160.0160.0170.021

0.0260.0240.0260.030

0.0330.0370.0470.059

0.0740.0900.1220.136

0.0400.0460.0560.071

0.0870.1030.1360.150

0.0350.0400.0500.064

0.0790.0950.1280.142

0.0250.0350.0350.045

0.0550.0710.0790.100

TABLE 6A DIMENSIONS OF PLAIN WASHERS FOR SEMS

0.1830.2140.2450.276

0.3070.3700.4330.495

0.6200.7270.8680.993

0.08600.09900.11200.1250

0.13800.16400.19000.2500

0.31250.37500.43750.5000

2345

68101/4

5/163/87/161/2

MAX. MIN. BASIC MAX. MIN.

0.0250.0250.0320.032

0.0320.0320.0400.063

0.0630.0630.0630.063

0.0280.0280.0360.036

0.0360.0360.0450.071

0.0710.0710.0710.071

0.0220.0220.0280.028

0.0280.0280.0360.056

0.0560.0560.0560.056

0.1880.2190.2500.281

0.3120.3830.4460.515

0.6400.7490.8901.015

WASHER THICKNESSWASHER OUTSIDE

DIAMETER

NOMINALSIZE

BASICSCREW

DIAMETER

NOMINALSIZE

BASICSCREW

DIAMETER

9

TABLE 7 DIMENSIONS

MAX.

J

HEXAGONSOCKET

SIZE

T F

0.0530.0590.0660.079

0.0920.1210.1520.182

0.2130.2440.306

4568

101/4

5/163/8

7/161/25/8

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.6250

0.1830.2050.2260.270

0.3120.3750.4370.562

0.6250.7500.875

0.1780.2000.2210.265

0.3070.3690.4310.556

0.6180.7430.867

0.0560.0620.0690.082

0.0950.1250.1560.187

0.2180.2500.312

0.0380.0440.0500.060

0.0720.0940.1200.145

0.1660.1840.250

0.0050.0060.0060.007

0.0090.0090.0120.015

0.0180.0200.024

0.0090.0100.0100.012

0.0140.0140.0170.020

0.0230.0260.032

HA

1/161/165/64

3/321/8

5/323/16

7/321/4

5/16

0.05000.0620.0620.078

0.0940.1250.1560.188

0.2190.2500.312

NOTES FOR TABLE 7

1. THREAD LENGTH. On all stock lengths the last complete (full form)thread measured with a thread ring gage (having the thread chamfer and/or counterbore removed) extends to within two threads of the head. Onother lengths and diameters the length of thread will conform to sockethead cap screw thread lengths.

2. SCREW LENGTH. The length of the screw is the distance measuredon a line parallel to the axis, from the plane of the bearing surface underthe head to the plane of the flat of the point. The basic length dimensionon the product shall be the nominal length, expressed as a two-placedecimal.

TABLE 7 HOLO-KROME SOCKET LOW HEAD CAP SCREWS

3. THREADS AND GAGING. Threads are Class 3A UNRC and UNRF withHolo-Krome controlled radius root and radiused runout. Acceptability ofscrew threads shall be based on System 22 of ANSI/ASME B1.3M.Class 3A threads do not provide a plating allowance. When plating isrequired, it is recommended that Holo-Krome supply the parts plated.

4. SOCKETS. Thermo-Forging®, a Holo-Krome patented process, pro-vides accurately formed sockets without broaching chips. BecauseThermo-Forging is not a machining process, it does not shear metal grainsand sockets can be deeper and much stronger.


Nominal Screw Length Standard Length Increment

1/8 thru 1/4 1/161/4 thru 1 1/81 thru 2 1/4


4 thru 3/8, 1/2 and 5/8,Inclusive Inclusive

Nominal Screw Length Tolerance on Length

Up to 1 in., Incl. -0.03 -0.03Over 1 in. to 2-1/2, Incl. -0.04 -0.06

Nominal Screw Size

MIN. MIN.

BASICSCREW

DIAMETERNOMINAL

SIZE NOM. MIN. MAX. MIN.MAX.

HEAD HEIGHTHEAD DIAMETERKEY

ENGAGEMENT FILLET EXTENSION

10

1/16

1/165/645/643/32

1/85/323/167/32

1/45/163/81/2

9/165/8

0.0250.0310.0380.044

0.0550.0610.0660.076

0.0870.1110.1350.159

0.1590.1720.2200.220

0.2480.297

0.05680.06950.08220.0949

0.10750.12020.13290.1585

0.18400.24350.30530.3678

0.42940.49190.61630.7406

0.86470.9886

0.0350.0500.050

J

MAX.

D A H

MIN.

FILLETEXTENSION

ABOVE D MAX

T F

HEAD DIAMETER

ABSOLUTEMIN.

MAX.THEO-

RETICALSHARP

HEAD HEIGHT

FLUSH-NESS

TOLER-ANCE NOM. MIN. MAX.

KEYENGAGE-

MENT

SPLINESOCKET

SIZE

HEXAGONSOCKET

SIZEREFER-ENCE

0.0060.0080.0100.010

0.0120.0140.0150.015

0.0150.0150.0150.015

0.0150.0150.0150.015

0.0150.015

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.0000

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.0000

0123

4568

101/4

5/163/8

7/161/25/83/4

7/81

TABLE 8 DIMENSIONSM

0.1380.1680.1970.226

0.2550.2810.3070.359

0.4110.5310.6560.781

0.8440.9381.1881.438

1.6881.938

0.1170.1430.1680.193

0.2180.2400.2630.311

0.3590.4800.6000.720

0.7810.8721.1121.355

1.6041.841

0.0440.0540.0640.073

0.0830.0900.0970.112

0.1270.1610.1980.234

0.2340.2510.3240.396

0.4680.540

0.0060.0070.0080.010

0.0110.0120.0130.014

0.0150.0160.0170.018

0.0180.0180.0220.024

0.0250.028

0.0480.0600.0600.072

0.0720.0960.0960.111

0.1450.1830.2160.251

0.2910.3720.4540.454

--

0.062

0.0620.0780.0780.094

0.1250.1560.1880.219

0.2500.3120.3750.500

0.5620.625

LENGTH TOLERANCES, L0 thru 3/8, 7/16 thru 3/4 7/8 thru 1-1/2,

Incl. Incl Incl.Nominal Screw Length Tolerance on Length

Up to 1 in., Incl. -0.03 -0.03 -0.05Over 1 in. to 2-1/2, Incl. -0.04 -0.06 -0.10

Over 2-1/2 to 6, Incl. -0.06 -0.08 -0.14Over 6 -0.12 -0.12 -0.20

1. THREAD LENGTH, LT.The length of the thread shall be measured,parallel to the axis of the screw, from the extreme point to the last complete(full form) thread.

2. SCREW LENGTH. The length of the screw is measured, parallel to thescrew axis, from the plane of the top of the head to the plane of the flat ofthe point. The basic length dimension on the product shall be the nominallength expressed as a two-place decimal.

3. THREADS. Threads are Class 3A UNRC and UNRF with Holo-Kromecontrolled radius root, and radiused runout.Class 3A threads do not provide a plating allowance. When plating isrequired, it is recommended that Holo-Krome supply the parts plated.

4. SOCKETS. Thermo-Forging®, a Holo-Krome patented process, pro-vides accurately formed sockets without broaching chips. BecauseThermo-Forging is not a machining process, it does not shear metal grainsand sockets can be deeper and much stronger.

5. HEAD DIAMETERS. The maximum sharp values under Column A aretheoretical values only as it is not practical to make the edges of the headsharp. The maximum sharp value represents the exact diameter of a holecountersunk to exactly 82° in which a screw having maximum head sizewill just fit flush.

6. HEAD HEIGHT. The tabulated values for head height are given forreference only and are calculated to the maximum formulation.

7. BEARING SURFACE. The axis of the conical bearing surface shall beparallel to the axis of the body within 1/2°.

STANDARD LENGTH TOLERANCES, LNominal Nominal Standard Length

Screw Size Screw Length Increment1/8 thru 1/4 1/16

0 to 1/4 thru 1 1/81 inch 1 thru 3-1/2 1/4Incl. 3-1/2 thru 7 1/2

7 thru 10 1

TABLE 8 HOLO-KROME SOCKET FLAT COUNTERSUNK HEAD CAP SCREWS

NOM.

Applicable Standards and SpecificationsASME/ANSI B18.3 and ASTM F835

Nominal Screw Size

BODYDIAMETER

BASICSCREW

DIAMETERNOMINAL

SIZE

11

NOMINALSIZE

OR BASICSCREW

DIAMETER

NOMINALSIZE

OR BASICSCREW

DIAMETER

TOTALTHREADLENGTH

THREADLENGTH

LT

LTT

MIN. MAX.

LT

LTT

THREADLENGTH

TOTALTHREADLENGTH

MIN. MAX.

0123

4568

101/45/163/8

0.500.620.620.62

0.750.750.750.88

0.881.001.121.25

0.620.770.800.83

0.991.001.051.19

1.271.501.711.94

1.381.501.752.00

2.252.50

2.172.382.823.25

3.694.12

TABLE 9 BODY AND GRIP LENGTHS

NOMINAL LENGTH

10 2 3 4 5 6 8 10

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

0.250.250.500.75

————

————

———

0.190.190.440.69

————

————

———

0.250.250.62

0.88———

————

———

0.170.170.55

0.80———

————

———

0.250.250.62

0.881.12——

————

———

0.160.160.54

0.791.04——

————

———

0.250.250.62

0.881.121.38—

————

———

0.150.150.52

0.771.021.27—

————

———

0.50

0.501.001.001.50

————

———

0.38

0.380.880.881.38

————

———

0.50

0.501.001.001.50

————

———

0.38

0.380.880.881.38

————

———

0.50

0.501.001.001.50

1.502.00——

———

0.34

0.340.840.841.34

1.341.84——

———

0.38

0.380.880.881.38

1.381.881.882.38

———

0.22

0.220.720.721.22

1.221.721.722.22

———

0.620.621.121.12

1.621.622.122.12

2.622.623.12

0.420.420.920.92

1.421.421.921.92

2.422.422.92

3/47/811-1/4

1-1/21-3/422-1/4

2-1/22-3/433-1/4

3-1/23-3/44

TABLE 9A (For Screws Beyond Sizes in Table 9)

5/161/4 3/8 7/16 1/2 5/8 3/4 7/8 1

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

LGH

LBH

0.77

0.771.271.271.77

1.772.272.272.77

2.773.273.273.77

3.774.27

1.041.04

1.041.801.801.80

2.542.542.543.30

3.303.30

1.50

1.501.501.502.50

2.502.502.503.50

3.503.50

1.00

1.001.001.002.00

2.002.002.003.00

3.003.00

1.501.501.501.50

2.502.502.502.50

3.503.50

0.940.940.940.94

1.941.941.941.94

2.942.94

0.880.880.88

0.881.881.881.88

1.882.88

1-3/422-1/42-1/2

2-3/433-1/43-1/2

3-3/444-1/44-1/2

4-3/455-1/45-1/2

5-3/46

0.750.751.251.25

1.751.752.252.25

2.752.753.253.25

3.753.754.25—

——

0.500.501.001.00

1.501.502.002.00

2.502.503.003.00

3.503.504.00—

——

0.880.881.38

1.381.881.882.38

2.382.882.883.38

3.383.883.884.38

4.384.88

0.600.601.10

1.101.601.602.10

2.102.602.603.10

3.103.603.604.10

4.104.60

1.001.00

1.501.502.002.00

2.502.503.003.00

3.503.504.004.00

4.504.50

0.690.69

1.191.191.691.69

2.192.192.692.69

3.193.193.693.69

4.194.19

1.12

1.121.621.622.12

2.122.622.623.12

3.123.623.624.12

4.124.62

1.00

1.001.001.751.75

1.752.502.502.50

3.253.253.254.00

4.004.00

0.62

0.620.621.361.36

1.362.122.122.12

2.862.862.863.62

3.623.62

1.501.50

1.502.252.252.25

3.003.003.003.75

3.753.75

1.501.501.50

1.502.502.502.50

2.503.50

NOTES FOR TABLES 9 AND 9A

1. GRIP GAGING LENGTH, LGH

. The grip gaging length is the distance,measured parallel to the axis of screw, from the top of the head to the firstcomplete (full form) thread under the head.

2. BODY LENGTH LBH

. The body length is the length, measured parallelto axis of screw, of the unthreaded portion of the shank and the headheight.

3. CONCENTRICITY. Concentricity of the thread with the body shall bewithin 0.005 in. per inch of body length (unthreaded portion) full (total)indicator reading, taken directly under the head when the screw is held bythe full threads closest to the head of the screw and shall not exceed 0.025in.

4. For screws of nominal lengths longer than those shown in Table 10, andfor screws over 1 in. in diameter, the L

GH max. and L

BH min. shall be

determined as shown in Table 10A: LGH

= (L-LT), L

BH = (L-L

TT).

TABLE 9 HOLO-KROME SOCKET FLAT COUNTERSUNK HEAD CAP SCREWS

NOMINAL SIZE

NOMINAL SIZE

NOMINAL LENGTH

0.43750.50000.62500.7500

0.87501.0000

7/161/25/83/4

7/81

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

12

NOTES FOR TABLE 101. THREAD LENGTH. On all stock lengths the last complete (full form)thread measured with a thread ring gage (having the thread chamfer and/or counterbore removed) extends to within two threads of the head. Onother lengths and diameters the length of thread will conform to SocketHead Cap Screw thread lengths.

2. SCREW LENGTH. The length of the screw is the distance measuredon a line parallel to the axis, from the plane of the bearing surface underthe head to the plane of the flat of the point. The basic length dimensionon the product shall be the nominal length expressed as a two-placedecimal.

3. THREADS AND GAGING. Threads are Class 3A UNRC and UNRFwith Holo-Krome controlled radium root and radiused runout. Acceptabil-ity of screw threads shall be based on System 22 of ANSI/ASME B1.3M.Class 3A threads do not provide a plating allowance. When plating isrequired, it is recommended that Holo-Krome supply the parts plated.

TABLE 10 HOLO-KROME SOCKET BUTTON HEAD CAP SCREWS

NOTE: THIS PRODUCT IS DESIGNEDFOR LIGHT FASTENING APPLICA-TIONS ONLY, SUCH AS SHEETMETALCOVERS, PLASTIC GUARDS, ETC. ITSHOULD NOT BE USED IN CRITICALHIGH STRENGTH APPLICATIONSWHERE SOCKET HEAD CAPSCREWSSHOULD BE USED.

TABLE 10 DIMENSIONS

1/16

1/165/645/643/32

1/85/323/167/32

5/163/8

0.0200.0280.0280.035

0.0350.0440.0440.052

0.0700.0870.1050.122

0.1750.210

0.1040.1290.1540.176

0.2010.2260.2500.298

0.3470.4190.5270.636

0.8510.970

0.0350.0500.050

J

MAX.

A H S

MIN.

FILLETEXTENSION

T F

NOM. MIN. MAX.

KEYENGAGE-

MENT

MAXIMUMSTANDARD

LENGTH

HEXAGONSOCKET

SIZE

HEADSIDE

HEIGHT

0.0100.0100.0100.010

0.0100.0100.0100.015

0.0150.0200.0200.020

0.0300.030

0.1140.1390.1640.188

0.2130.2380.2620.312

0.3610.4370.5470.656

0.8751.000

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.50000.6250

0123

4568

101/4

5/163/8

1/25/8

L

0.0320.0390.0460.052

0.0590.0660.0730.087

0.1010.1320.1660.199

0.2650.331

0.0260.0330.0380.044

0.0510.0580.0630.077

0.0910.1220.1520.185

0.2450.311

0.0100.0100.0100.010

0.0150.0150.0150.015

0.0200.0310.0310.031

0.0460.062

0.0480.0600.0600.072

0.0720.0960.0960.111

0.1450.1830.2160.251

0.3720.454

1/21/21/21/2

1/21/25/83/4

111

1-1/4

22

0.062

0.0620.0780.0780.094

0.1250.1560.1880.219

0.3120.375

NOM.

HEADDIAMETER

BASICSCREW

DIAMETERNOMINAL

SIZEMAX. MIN.

HEADDIAMETER

REF.

M

SPLINESOCKET

SIZE

NOM. MIN.

0.0050.0050.0050.005

0.0050.0050.0050.010

0.0100.0150.0150.015

0.0200.020


Nominal Screw Length Standard Length Increment1/8 thru 1/4 1/161/4 thru 1 1/81 thru 2 1/4

LENGTH TOLERANCES0 thru 3/8, 1/2 and 5/8,

Nominal Screw Size Inclusive Inclusive

Nominal Screw Length Tolerance on Length

Up to 1 in., Inc. -0.03 -0.03Over 1 in. to 2-1/2, Incl. -0.04 -0.06

Applicable Standards and SpecificationsASME/ANSI B18.3 and ASTM F835

4. SOCKETS. Thermo forging®, a Holo-Krome patented process, pro-vides accurately formed sockets without broaching chips. BecauseThermo-Forging is not a machining process, it does not shear metalgrains and sockets can be deeper and much stronger.

5. FILLET. For all lengths of screws, the form of the filet shall be optional,provided it fairs into the bearing surface within the limits of the threadmajor diameter maximum plus F maximum, and the thread major diam-eter minimum, plus F minimum and is smooth and continuous curvehaving a bearing surface juncture radius no less than that tabulatedbelow:

NominalScrewSize

01234568

JunctureRadius

Min.

.002

.003

.003

.004

.004

.005

.005

.006

NominalScrewSize

101/45/163/81/25/8

JunctureRadius

Min.

.006

.007

.009

.012

.016

.021

6. BEARING SURFACE. The plane of the bearing surface shall beperpendicular to the axis of the shank within 2°.

13

0.02800.03500.05000.0625

0.07810.09370.10940.1250

0.14060.15620.18750.2187

0.25000.31250.37500.4375

0.50000.56250.62500.7500

0.87501.00001.2500

MAX.

J

MIN.

0.02850.03550.05100.0635

0.07910.09520.11110.1270

0.14260.15870.19000.2217

0.25300.31600.37900.4420

0.50500.50800.63100.7570

0.88501.01001.2650

0.0280.0350.0501/16

5/645/327/641/8

9/645/323/167/32

1/45/163/8

7/16

1/29/165/83/4

7/81

1-1/4

SOCKET WIDTHACROSS FLATS

NOMINALSOCKET

SIZE

TABLE 11 HOLO-KROME HEXAGON AND SPLINE SOCKETS

TABLE 11 DIMENSIONSHEXAGON

NOMINALSOCKETAND KEY

SIZE

NUMBEROF

TEETH MAX.

M

MIN.

SOCKET MAJORDIAMETER

MAX.

N

MIN.

SOCKET MINORDIAMETER

MAX.

P

MIN.

WIDTH OFTOOTH

0.0330.0480.0600.072

0.0960.1110.1330.145

0.1680.1830.2160.251

0.2910.3720.4540.595

0.6200.6980.790

0.01150.0100.0130.015

0.0210.0230.0280.030

0.0330.0370.0480.058

0.0660.0890.1090.134

0.1450.1640.185

0.0120.0110.0140.016

0.0220.0250.0300.032

0.0360.0390.0500.060

0.0680.0920.1120.138

0.1490.1680.189

0.02550.0400.0500.063

0.0800.0960.1160.126

0.1470.1610.1880.219

0.2520.3160.3830.506

0.5310.6000.681

0.0260.0410.0510.064

0.0820.0980.1180.128

0.1500.1630.1900.221

0.2540.3190.3860.509

0.5350.6040.685

0.0340.0490.0610.073

0.0970.1130.1350.147

0.1710.1860.2190.254

0.2960.3770.4600.601

0.6270.7050.797

0.0350.0500.0620.074

0.0980.1150.1370.149

0.1730.1880.2210.256

0.2980.3800.4630.604

0.6310.7090.801

4666

6666

6666

6666

666

NOTE: Sockets up to 1" in nominal size should not be evaluated by direct measurement, but checked with goand no-go gages as specified in ASME/ANSI B18.3.

NOTES FOR TABLE 11

1. SOCKET DEPTH (T) - Applicable socket depths are specified in thedimensional tables and notes for the respective screw types.

2. SOCKET CHAMFER. Where hexagon sockets are chamfered, the depth ofchamfer shall not exceed 10 per cent of the nominal socket size for sizes up toand including 1/16 in., and 7.5 per cent for larger sizes. For chamfered sockets, itis permissible for the NOT GO socket gage to enter to the dept of chamfer asspecified in ASME/ANSI B 18.3.

SPLINE

14

NOMINAL THREADSIZE OR BASIC

THREAD DIAMETER

TABLE 12 HOLO-KROME SOCKET HEAD SHOULDER SCREWS

TABLE 12 DIMENSIONS

1/4 0.250 0.2480 0.2460 0.375 0.357 0.188 0.177 0.157 1/8 0.125 0.094 0.014 0.0095/16 0.312 0.3105 0.3085 0.438 0.419 0.219 0.209 0.183 5/32 0.156 0.117 0.017 0.0123/8 0.375 0.3730 0.3710 0.562 0.543 0.250 0.240 0.209 3/16 0.188 0.141 0.020 0.0151/2 0.500 0.4980 0.4960 0.750 0.729 0.312 0.302 0.262 1/4 0.250 0.188 0.026 0.020

5/8 0.625 0.6230 0.6210 0.875 0.853 0.375 0.365 0.315 5/16 0.312 0.234 0.032 0.0243/4 0.750 0.7480 0.7460 1.000 0.977 0.500 0.490 0.421 3/8 0.375 0.281 0.039 0.0301 1.000 0.9980 0.9960 1.312 1.287 0.625 0.610 0.527 1/2 0.500 0.375 0.050 0.040

1-1/4 1.250 1.2480 1.2460 1.750 1.723 0.750 0.735 0.633 5/8 0.625 0.469 0.060 0.050

1-1/2 1.500 1.4980 1.4960 2.125 2.095 1.000 0.980 0.842 7/8 0.875 0.656 0.070 0.0601-3/4 1.750 1.7480 1.7460 2.375 2.345 1.125 1.105 0.948 1 1.000 0.750 0.080 0.070

2 2.000 1.9980 1.9960 2.750 2.720 1.250 1.230 1.054 1-1/4 1.250 0.937 0.090 0.080

D(1) A H S J T M

NOMINAL SIZEOR BASIC

SHOULDERDIAMETER

SHOULDERDIAMETER

MAX. MIN. MAX. MIN. MAX. MIN. MIN. NOM. MIN. MAX. MIN.

HEXAGONSOCKET SIZE

KEYENGAGEMENT

HEAD FILLETEXTENSION ABOVE D

HEADHEIGHT

HEADSIDE HEIGHT

HEADDIAMETER

NOMINAL SIZEOR BASIC

SHOULDERDIAMETER

K F DT G I N E(3)

SHOULDERNECK

DIAMETER

SHOULDERNECKWIDTH

MIN. MAX. MAX. MIN. MAX MAX. MIN. BASIC

THREADSPERINCH

THREADNECK

DIAMETER

THREADNECKWIDTH

THREADNECKFILLET

THREADLENGTH

1/4 0.250 0.227 0.093 10 0.1900 24 0.142 0.133 0.083 0.023 0.017 0.3755/16 0.312 0.289 0.093 1/4 0.2500 20 0.193 0.182 0.100 0.028 0.022 0.4383/8 0.375 0.352 0.093 5/16 0.3125 18 0.249 0.237 0.111 0.031 0.025 0.5001/2 0.500 0.477 0.093 3/8 0.3750 16 0.304 0.291 0.125 0.035 0.029 0.625

5/8 0.625 0.602 0.093 1/2 0.5000 13 0.414 0.397 0.154 0.042 0.036 0.7503/4 0.750 0.727 0.093 5/8 0.6250 11 0.521 0.502 0.182 0.051 0.045 0.8751 1.000 0.977 0.125 3/4 0.7500 10 0.638 0.616 0.200 0.055 0.049 1.000

1-1/4 1.250 1.227 0.125 7/8 0.8750 9 0.750 0.726 0.222 0.062 0.056 1.125

1-1/2 1.500 1.478 0.125 1-1/8 1.1250 7 0.964 0.934 0.286 0.072 0.066 1.5001-3/4 1.750 1.728 0.125 1-1/4 1.2500 7 1.089 1.059 0.286 0.072 0.066 1.750

2 2.000 1.978 0.125 1-1/2 1.5000 6 1.307 1.277 0.333 0.102 0.096 2.000

TABLE 12 DIMENSIONS (continued)

15

NOTES FOR TABLE 12

1. SHOULDER. Shoulder refers to the enlarged unthreaded portion ofthe screw, the diameter of which serves as the basis for derivation ofthe nominal size. The maximum shoulder diameter is 0.002 less thanthe nominal size.

2. LENGTH. The length of screw shall be measured parallel to the axisof screw from the plane of the bearing surface under the head to theplane of the shoulder at threaded end. The basic length dimension ofthe product shall be the nominal length of the shoulder, expressed as athree-place decimal.

STANDARD LENGTHS. The difference between consecutive lengths ofstandard screws shall be as designated in the following tabulation:

3. THREAD LENGTH TOLERANCE. The tolerance on thread length Eshall be -0.020 in. for screw sizes up to 3/8 in. inclusive, and -0.030 in.for screw sizes larger than 3/8 in.

4. NECK AND FILLET UNDER HEAD. The screws may be neckedunder the head at option of Holo-Krome. The fillet at the intersection ofthe head bearing surface and neck or shoulder shall be above D withinthe tabulated limits for M.

5. NECK UNDER SHOULDER. The neck under the shoulder shallallow the shoulder to seat against the face of a standard basic GOthread ring gage.

6. BEARING SURFACE. The plane of the bearing surface of the headshall be perpendicular to the axis of the shoulder within a maximumdeviation of two degrees.

7. CONCENTRICITY. Head shall be concentric with the shoulderwithin 1 per cent (2 per cent total runout) of the nominal diameter D or0.003 in. (0.006 in. total runout), whichever is greater.

Pitch diameter and shoulder shall be concentric within 0.004 in.total runout when checked at a distance of 0.188 in. from the shoulderat the threaded end.

Concentricity, parallelism, bow and squareness of shoulder tothread, shall be within 0.005 in. total runout per inch of shoulder length,with a maximum of 0.025 in., when firmly seated against the shoulder ina threaded bushing, and checked on the shoulder a distance 2F fromthe underside of the head. Threads of bushing shall be basic size, andbushing OD and ends shall be concentric and square with the axis.

8. THREADS AND GAGING. Threads are Class 3A UNRC and UNRFwith Holo-Krome controlled radius root. Acceptability of screw threadsshall be based on System 22 of ANSI/ASME B1.3M.

Class 3A threads do not provide a plating allowance. Whenplating is required, it is recommended that Holo-Krome supply the partsplated.

Applicable Standards and SpecificationsASME/ANSI B18.3

Nominal Screw(Shoulder) Length

1/4 thru 3/43/4 thru 5

Over 5

Standard LengthIncrement

1/81/41/2

HOLO-KROME SOCKET HEAD SHOULDER SCREWS

16

TABLE 13 DIMENSIONSC

2J(4)

NOM.

HEXAGONSOCKET

SIZE

SPLINESOCKET

SIZE

M(4) R

OVALPOINT

RADIUS

NOM. MIN.MAX.

C1T (3)

MIN KEY ENGAGEMENTTO DEVELOP FUNCTIONAL

CAPABILITY OF KEY

SPLINESOCKETT

S MIN.

HEXSOCKETTH MIN. MAX. MIN.

Y

CONE POINT ANGLE90° ±2°

FOR THESE NOMINALLENGTHS OR LONGER:

118° ±2°FOR SHORTER

NOMINAL LENGTHS

0123

4568

101/4

5/163/8

7/161/25/83/4

7/81

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.0000

0.0280.0350.0350.050

0.0501/161/165/64

3/321/85/323/16

7/321/45/163/8

1/29/16

0.0620.0620.078

0.0940.1250.1560.188

0.2190.2500.3120.375

0.5000.562

0.0500.0600.0600.070

0.0700.0800.0800.090

0.1000.1250.1560.188

0.2190.2500.3120.375

0.5000.562

BASIC

NOTES FOR TABLE 131. LENGTH - The length of the screw shall be measured overall, parallelto axis of screw. The basic length dimension on the product shall be thenominal length expressed as a two-place decimal.

2. THREADS AND GAGING. Threads shall be Unified external thread;Class 3A, UNC and UNF Series. Acceptability of screw threads shallbased on System 22 of ANSI/ASME B1.3M.

Since standard gages provide only for engagement lengths up to 1-1/2 diameters, changes in pitch diameter of either or both external andinternal thread may be required for longer lengths of engagement.

Class 3A does not provide a plating allowance. When platedproducts are required, it is recommended that Holo-Krome supply theparts plated.

3. SOCKET DEPTHS. The key engagement dimensions given in columnsTH and TS of Table 13 shall apply only to nominal screw lengths equal toor longer than the lengths listed in Columns B and B1, respectively. Forhexagon socket key engagement dimensions in screws of shorter nominallengths than listed in Column B of Table 13, see Table 14. Spline socketsin screws shorter than those listed in Column B1 of Table 13 shall be asdeep as practicable.

4. SOCKETS. Thermo-Forging®, a Holo-Krome patented process, pro-vides accurately formed sockets without broaching chips. BecauseThermo-Forging is not a machining process, it does not shear metal grainsand the sockets can be deeper and much stronger.

TABLE 13 HOLO-KROME SOCKET SET SCREWS

FLATPOINT

DIAMETERS

CUPPOINT

DIAMETERS

0.0330.0330.0480.048

0.0600.0720.0720.096

0.1110.1450.1830.216

0.2510.2910.3720.454

0.595–

0.0260.0350.0400.040

0.0450.0550.0550.080

0.0800.1250.1560.188

0.2190.2500.3120.375

0.500–

0.0320.0380.0430.050

0.0560.0620.0690.082

0.0950.1250.1560.187

0.2180.2500.3120.375

0.4370.500

0.0270.0330.0380.045

0.0510.0560.0620.074

0.0860.1140.1440.174

0.2040.2350.2950.357

0.4180.480

0.0330.0400.0470.054

0.0610.0670.0740.087

0.1020.1320.1720.212

0.2520.2910.3710.450

0.5300.609

0.0270.0330.0390.045

0.0510.0570.0640.076

0.0880.1180.1560.194

0.2320.2700.3470.425

0.5020.579

0.0450.0550.0640.074

0.0840.0940.1040.123

0.1420.1880.2340.281

0.3280.3750.4690.562

0.6560.750

0.090.090.130.13

0.190.190.190.25

0.250.310.380.44

0.500.570.750.88

1.001.13


NOMINAL SCREW LENGTH TOLERANCE ON LENGTH

Up to 5/8, Incl.. ± 0.01Over 5/8 to 2, Incl. ± 0.02Over 2 to 6, Incl. ± 0.03

Over 6 ± 0.06

* Applicable only to sizes 0 (0.060 in.) through 3 (0.099 in.), inclusive.


NOMINAL SCREW LENGTH STANDARD LENGTH INCREMENT

1/16 thru 3/16* .031/8 thru 1/2 .061/2 thru 1 .121 thru 2 .252 thru 6 .50Over 6 1.00

NOMINALSIZE

BASICSCREW

DIAMETER

17

HOLO-KROME SOCKET SET SCREWS

5. CHAMFER. On screws longer than minimum lengths listed inColumn B or B1, the face will normally be chamfered between 30° and45°. Shorter screws will be chamfered where possible.

In special applications where stripping is a problem, Holo-Kromemay be able to supply unchamfered screws to provide additionalstength.

6. POINT ANGLE. The angle on flat and cup point set screws is 45° plus5° minus 0° for screws of lengths equal to or longer than those listed inColumn B or B1; and 30° minimum for shorter screws.

The point angle applies only to that portion of the angle below thethread root diameter.

7. OVAL POINT. The oval point radius tolerance is + 0.015 inches for

nominal sizes through 5, and + 0.031 inches for screws 6 and over.

8. HALF DOG POINT ECCENTRICITY. The permissible eccentricityof the half dog axis, with respect to the axis of the thread, shall notexceed 3 per cent of the basic diameter of the screw, and in no case shallbe greater than 0.005 in. for sizes up to and incl. 3/4 in. For sizes over3/4 in. it shall not be greater than 0.010 in. (Total runout shall not exceedtwice the permissible eccentricity.)

9. CONE POINT CONFIGURATION. The apex of the cone may beflattened or rounded to the extent of 10 per cent of the basic diameterof the screw.

Applicable Standards and SpecificationsASME/ANSI B18.3 and ASTM F912.

TABLE 13 DIMENSIONS (Continued)

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.0000

0123

4568

101/45/163/8

7/161/25/83/4

7/81

HALF DOGPOINTS

CUP ANDFLAT POINTS

HALF DOGPOINTS

DIAMETER

HALF DOG POINT

P Q

MAX. MIN.

LENGTH

MAX. MIN.CUP AND

FLAT POINTS

B

SHORTEST OPTIMUM NOMINAL LENGTHTO WHICH COLUMN TH APPLIES

B1

SHORTEST OPTIMUM NOMINAL LENGTHTO WHICH COLUMN T

S APPLIES

0.0400.0490.0570.066

0.0750.0830.0920.109

0.1270.1560.2030.250

0.2970.3440.4690.562

0.6560.750

0.0370.0450.0530.062

0.0700.0780.0870.103

0.1200.1490.1950.241

0.2870.3340.4560.549

0.6420.734

0.0170.0210.0240.027

0.0300.0330.0380.043

0.0490.0670.0820.099

0.1140.1300.1640.196

0.2270.260

0.0130.0170.0200.023

0.0260.0270.0320.037

0.0410.0590.0740.089

0.1040.1200.1480.180

0.2110.240

0.130.130.130.19

0.190.190.190.19

0.190.250.310.38

0.440.500.630.75

0.881.00

0.130.190.190.19

0.190.190.250.25

0.250.310.440.44

0.630.630.881.00

1.001.25

0.130.130.190.19

0.190.190.190.25

0.250.310.380.44

0.500.630.881.00

1.001.25

0.060.130.130.13

0.130.130.130.19

0.190.250.310.38

0.440.500.630.75

0.88–

0.130.190.190.19

0.190.190.250.25

0.250.310.440.44

0.630.630.881.00

1.25–

0.130.130.190.19

0.190.190.190.25

0.250.310.380.44

0.500.630.881.00

1.00–

NOMINALSIZE

BASICSCREW

DIAMETER90° CONE ANDOVAL POINTS

90°. CONE ANDOVAL POINTS

18

TABLE 14 HOLO-KROME SOCKET SET SCREWS

1CAUTION: The use of products listed in Table 14 can result in failure of the socket key, or mating threads during tightening because key engagementand thread length are less than optimum. Therefore, it is strongly recommended that screws of lengths equal to or greater than the lengths specifiedin Columns B and B1 of Table 13 be used wherever possible.

2See Table 13 and the illustrations and notes thereto, for additional dimensions and specifications.

3These products are covered in Table 13.

4These sizes are impractical to manufacture because of point configuration and short length.

5Cone point angle for these lengths shall be 90°; see Column Y in Table 13.

6Cup angle may be 118° or 130°, ± 5°, depending upon screw length and manufacturing process.

TABLE 14 HEXAGON KEY ENGAGEMENTS FOR SHORT LENGTH SET SCREWS 1, 2

J L

CUP6 ANDFLAT POINTS

TH

118° CONE ANDOVAL POINTS

MINIMUM KEY ENGAGEMENT

HALF DOG POINT

NOMINALSCREW

LENGTHS1NOM.

HEXAGONSOCKET SIZE

0

1

2

3

4

5

6

8

10

1/4

5/16

3/8

7/16

1/2

5/8

3/4

7/8

1

0.0600

0.0730

0.0860

0.0990

0.1120

0.1250

0.1380

0.1640

0.1900

0.2500

0.3125

0.3750

0.4375

0.5000

0.6250

0.7500

0.8750

1.0000

0.028

0.035

0.035

0.050

0.050

1/16

1/16

5/64

3/32

1/8

5/32

3/16

7/32

1/4

5/16

3/8

1/2

9/16

0.062

0.062

0.078

0.094

0.125

0.156

0.188

0.219

0.250

0.312

0.375

0.500

0.562

0.060.09

0.060.09

0.060.09

0.090.13

0.090.13

0.090.13

0.090.130.16

0.130.160.19

0.130.19

0.190.25

0.250.31

0.250.310.50

0.380.44

0.380.440.50

0.50

0.630.75

0.750.87

0.750.851.00

0.0300.040

0.0300.040

0.0300.040

0.0400.055

0.0450.060

0.0400.060

0.0400.0600.070

0.0600.070

—3

0.060—3

0.090—3

0.125—3

0.1100.140

—3

0.160—3

0.1750.215

—3

0.205

0.255—3

0.330—3

0.2800.380

—3

0.0280.0405

0.0290.0405

0.0290.040

0.0390.0405

0.0390.045

0.0390.045

0.0390.0450.065

0.0500.0600.065

0.0420.060

0.0650.110

0.0990.140

0.0900.1150.165

0.1250.160

0.1300.1550.195

0.145

0.1900.325

0.2550.419

0.1750.2800.380

—4

0.028

—4

0.040

—4

0.035

—4

0.045

—4

0.045

—4

0.045

—4

0.0450.065

0.0450.0600.065

0.0420.060

0.0550.090

0.0900.105

0.0750.1050.155

0.1250.160

0.1300.1550.195

0.145

0.1900.295

0.2250.330

0.1750.2800.380

BASICSCREW

DIAMETERNOMINAL

SIZE

19

NOMINALSIZE

MIN.

THREADSIZE

A

MAX.

D

MAX. MIN. MIN.

PL

MAX.

P T

1/4

5/16

3/8

7/16

1/2

5/8

3/4

7/8

1

#8-32 UNC-2B

#10-32 UNF-2B

#10-32 UNF-2B

#10-32 UNF-2B

1/4-20 UNC-2B

1/4-20 UNC-2B

5/16-18 UNC-2B

3/8-16 UNC-2B

3/8-16 UNC-2B

0.237

0.298

0.359

0.417

0.480

0.605

0.725

0.850

0.975

0.2503

0.3128

0.3753

0.4378

0.5003

0.6253

0.7503

0.8753

1.0003

0.031

0.034

0.038

0.047

0.047

0.047

0.059

0.059

0.059

0.500

0.625

0.625

0.625

0.750

0.750

0.875

0.875

0.875

0.250

0.344

0.344

0.344

0.375

0.375

0.375

0.375

0.375

Applicable Standards and SpecificationsASME/ANSI B18.8.2.

TABLE 16 DIMENSIONS

0.2501

0.3126

0.3751

0.4376

0.5001

0.6251

0.7501

0.8751

1.0001

TABLE 15 HOLO-KROME DOWEL PINS

TABLE 16 HOLO-KROME PULL DOWEL PINS

NOMINALSIZE

TABLE 15 DIMENSIONS

DIAMETER D

STANDARD PIN

MAX. MIN. MAX. MIN.

OVERSIZE PIN

0.031

0.046

0.062

0.062

0.078

0.093

0.109

0.125

0.125

0.125

0.125

0.045

0.060

0.070

0.070

0.080

0.090

0.090

0.090

0.120

0.120

0.120

0.1259

0.1884

0.2509

0.3134

0.3759

0.4384

0.5009

0.6259

0.7509

0.8759

1.0009

0.1261

0.1886

0.2511

0.3136

0.3761

0.4386

0.5011

0.6261

0.7511

0.8761

1.0011

0.1251

0.1876

0.2501

0.3126

0.3751

0.4376

0.5001

0.6251

0.7501

0.8751

1.0001

0.1253

0.1878

0.2503

0.3128

0.3753

0.4378

0.5003

0.6253

0.7503

0.8753

1.0003

1/8

3/16

1/4

5/16

3/8

7/16

1/2

5/8

3/4

7/8

1

RPL

1. Point length is decreased and point angle increased on short dowel pins.

Applicable Standards and SpecificationsASME/ANSI B18.8.2

POINTLENGTH

(REF.)

TOPRADIUSBASIC

20

TABLE 17 DIMENSIONS (3)C

MIN.

K

MAX.MIN.

NOMINALKEY OR BIT

ANDSOCKET SIZE

HEXAGON WIDTHACROSS FLATS

MAX. MIN.

W

HEXAGON WIDTHACROSS CORNERS

MAX. MIN.

Y

LENGTH OFSHORT ARM

MAX. MIN.

B

MAX. MIN.

LENGTH OF LONG ARM

SHORT SERIES LONG SERIES

MAX.

R

RADIUSOF BEND CHAMFER

1/16

5/643/327/641/8

9/645/323/167/32

1/45/163/87/16

1/29/165/83/4

7/811-1/41-1/2

0.062

0.0780.0940.1090.125

0.1410.1560.1880.219

0.2500.3120.3750.438

0.5000.5620.6250.750

0.8751.0001.2501.500

0.0280.0350.050

0.02800.03500.05000.0625

0.07810.09370.10940.1250

0.14060.15620.18750.2187

0.25000.31250.37500.4375

0.50000.56250.62500.7500

0.87501.00001.25001.5000

0.02750.03450.04900.0615

0.07710.09270.10790.1235

0.13910.15470.18600.2172

0.24850.31100.37350.4355

0.49750.56000.62250.7470

0.87200.99701.24301.4930

0.03140.03930.05600.0701

0.08800.10580.12380.1418

0.15930.17740.21350.2490

0.28450.35700.43000.5018

0.57350.64520.71690.8603

1.00361.1470

——

0.03000.03780.05400.0680

0.08590.10350.12100.1390

0.15660.17450.21050.2460

0.28150.35310.42380.4944

0.56500.63560.70800.8512

0.99311.1350

——

0.3120.4380.6250.656

0.7030.7500.7970.844

0.8910.9381.0311.125

1.2191.3441.4691.594

1.7191.8441.9692.219

2.4692.7193.2503.750

0.1250.2500.4380.469

0.5160.5620.6090.656

0.7030.7500.8440.938

1.0311.1561.2811.406

1.5311.6561.7812.031

2.2812.5312.7503.250

1.3121.3121.7501.844

1.9692.0942.2192.344

2.4692.5942.8443.094

3.3443.8444.3444.844

5.3445.8446.3447.344

8.3449.344

11.50013.500

1.1251.1251.5621.656

1.7811.9062.0312.156

2.2812.4062.6562.906

3.1563.6564.1564.656

5.1565.6566.1567.156

8.1569.156

11.00013.000

2.6882.7662.9383.094

3.2813.4693.6563.844

4.0314.2194.5944.969

5.3446.0946.8447.594

8.3449.0949.844

11.344

12.84414.344

——

2.5002.5782.7502.906

3.0943.2813.4693.656

3.8444.0314.4064.781

5.1565.9066.6567.406

8.1568.9069.656

11.156

12.65614.156

——

0.0620.0620.0620.062

0.0780.0940.1090.125

0.1410.1560.1880.219

0.2500.3120.3750.438

0.5000.5620.6250.750

0.8751.0001.2501.500

0.0030.0040.0060.008

0.0080.0090.0140.015

0.0160.0160.0220.024

0.0300.0320.0440.047

0.0500.0530.0550.070

0.0760.0810.0920.104

1. Each end is square with the axis of each arm within 4° and edges maybe sharp or chamfered at the option of Holo-Krome, the chamfer not toexceed K.

2. For nominal socket sizes above 1 in. it is recommended that bits be usedin conjunction with standard hexagon wrenches or power drives. Bits areavailable, but lengths are not standardized.

TABLE 17 ALLEN WRENCHES AND BITS

3. For plated wrenches and bits, all dimensions are before plating.

Applicable Standards and SpecificationsASME/ANSI B18.3 and GGG-K-275 Amend. 1 (Reference)

21

TABLE 18 ALLEN SPLINE KEYS AND BITS

TABLE 18 DIMENSIONS (2)R

MAX.

C

LENGTH OF LONG ARM

MIN.

M

MAJORDIAMETER

MAX.

SHORT SERIES

RADIUSOF BEND

K

CHAM-FER

0.0330.0480.0600.072

0.0960.1110.1330.145

0.1680.1830.2160.251

0.291.372.454.595

.620

.698

.790

1. Each end is square with the axis of each arm within 4° and edgesmay be sharp or chamfered at the option of Holo-Krome, the chamfernot to exceed K.

NOMINALKEY OR BIT

ANDSOCKET SIZE

0.0030.0040.0060.008

0.0080.0090.0140.015

0.0160.0160.0220.024

0.0300.0320.0440.050

0.0530.0550.070

MIN.

0.0620.0620.0620.062

0.0780.0940.1250.125

0.1560.1560.1880.219

0.2500.3120.3750.500

0.5000.5620.625

LONG SERIES

MIN.MAX.MIN.MAX.

————

——

3.6563.844

4.0314.2194.5944.969

5.3446.0946.8448.344

9.094——

1.1251.1251.5621.656

1.7811.9062.0312.156

2.2812.4062.6562.906

3.1563.6564.1565.156

5.6565.6566.156

1.3121.3121.7501.844

1.9692.0942.2192.344

2.4692.5942.8443.094

3.3443.8444.3445.344

5.8445.8446.344

MIN.

0.1250.2500.4380.469

0.5160.5620.6090.656

0.7030.7500.8440.938

1.0311.1561.2811.531

1.6561.6561.781

LENGTH OFSHORT ARM

B

MAX.

0.3120.4380.6250.656

0.7030.7500.7970.844

0.8910.9381.0311.125

1.2191.3441.4691.719

1.8441.8441.969

0.01300.01200.01500.0180

0.02300.02700.03200.0340

0.03900.04250.05350.0640

0.0760.0960.1170.1445

.1590

.1780

.1950

0.01400.01300.01600.0190

0.02400.02800.03400.0355

0.04100.04400.05500.0655

0.0775.0975.1185.1460

.1615

.1805

.1975

MIN.

WIDTH OFSPACE

N

MAX.

NO.OF

SPLINES

4666

6666

6666

6666

666

0.02400.03800.04800.0610

0.07750.09250.11200.1225

0.14200.15650.18250.2125

0.2445.3085.3755.4975

.5215

.5905

.6715

W

MINORDIAMETER

MIN.MAX.

0.03200.04700.05900.0710

0.09500.11000.13100.1435

0.16600.18150.21450.2495

0.2895.3705.4525.5935

.6175

.6955

.7875

0.03300.04800.06000.0720

0.09600.11100.13300.1450

0.16800.18300.21600.2510

0.2910.3720.4540.5950

.6200

.6980

.7900

0.02500.03900.04900.0620

0.07900.09400.11400.1240

0.14400.15800.18400.2140

0.2460.3100.3770.5000

.5240

.5930

.6740

————

——

3.4693.656

3.8444.0314.4064.781

5.1565.9066.6568.156

8.906——

2. For plated keys and bits, all dimensions are before plating.

3. Bits are available, but lengths have not been standardized.

Applicable Standards and SpecificationsASME/ANSI B18.3 and GGG-K-275 Amend. 1 (Reference)

22

TABLE 19 HOLO-KROME SOCKET PRESSURE PLUGS — DRYSEAL (NPTF) TYPE — 3/4 TAPER

NOTES FOR TABLE 19

1. THREADS - Threads conform to the American Standard TaperDryseal Pipe Thread NPTF in accordance with specifications andgaging requirements described in ANSI B2.2.

2. THREAD CHAMFERS - Both ends of the plug shall be flat andchamfered approximately 90° angle included. The chamfer shall ex-tend slightly below the root of the thread, and the edge between the flatand the chamfer may be slightly rounded.

3. LENGTH - The length of the plug shall be measured overall on a lineparallel to the axis.

4. SOCKETS - See Page 13 Table 11, for hexagon socket dimensions.A slight chamfer, radius or countersink on the hexagon socket ispermissible.

TABLE 19 DIMENSIONS — DRYSEAL TYPE — 3/4 TAPERD L (3)

NOMINALO.D.

THREADSPERINCH

NOMINALSIZE

J

NOM.

HEX SOCKETSIZE

MIN.

KEYENGAGEMENT

T G

WALLTHICKNESS

MIN. NOM. MAX. MIN.

LENGTH

1/161/81/43/8

1/23/411-1/4

1-1/22

.312

.405

.540

.675

.8401.0501.3151.660

1.9002.375

27271818

141411-1/211-1/2

11-1/211-1/2

5/323/161/45/16

3/89/165/83/4

11

0.1560.1870.2500.312

0.3750.5620.6250.750

1.0001.000

HOLO-KROME HEXAGON SOCKET PRESSURE PLUGS —DRYSEAL (NPTF) — The Holo-Krome Dryseal Pressure Plug is a plugthat has a tapered (3/4 inch diametral per foot) thread extending itsentire length and is designed to have its threads mesh tightly with thoseof a taper-threaded hole. The thread truncation is closely controlled atroot and crest to ensure metal-to-metal contact at these points,

coincident to or prior to flank contact. This prevents spiral leakage andprovides more positive sealing. Holo-Krome Dryseal NPTF pressureplugs can be used in NPT tapped holes, but for best protection againstleakage they should be used in dryseal tapped holes that are taperreamed before tapping.

5. DESIGNATION - Each of the letters in the symbol has a definitesignificance as follows:

N = USA (American) StandardP = PipeT = TaperF = Fuel and Oil3/4= 0.750 inch taper per 12 inches

Applicable Standards and SpecificationsANSI B2.2 and ANSI B1.20.3

0.1400.1400.2180.250

0.3120.3120.3750.437

0.4370.437

0.0620.0620.0730.084

0.0950.1250.1250.156

0.1560.156

0.3120.3120.4380.500

0.5620.6250.7500.812

0.8120.875

0.3240.3240.4570.520

0.5820.6450.7700.832

0.8430.906

0.3000.3000.4170.480

0.5420.6050.7300.792

0.7800.844

23

TABLE 20 HOLO-KROME SOCKET PRESSURE PLUGS — FLUSH (PTF) TYPE — 7/8 TAPER

HOLO-KROME HEXAGON SOCKET PRESSURE PLUGS — FLUSHTYPE (PTF — 7/8). The Holo-Krome flush type plug is a plug having atapered thread (7/8" diametral per foot) extending its entire length anddesigned to provide a flush condition with a standard taper-tapped hole

(3/4" diametral per foot). It achieves a high pressure seal through thedifference in taper, with dimensions precalculated to provide a highersealing load near the large end of the plug and the threads near the topof the tapped hole. It is used in applications where high pressures areencountered and where protrusion is undesirable.

NOTES FOR TABLE 20

1. THREADS - Threads conform to ANSI B2.2 Dryseal Taper PipeThread. Taper: 7/8" diametral per foot.

PITCH DIAMETER - The pitch diameter at the socket face is thediametral equivalent of one-half thread larger than the pitch diameter(E1) of a standard pipe thread taper-tapped hole (3/4 diametral taperper foot). This provides the basic point of thread interference to producea high pressure sealed joint.

2. THREAD CHAMFERS - Both ends of the plug shall be flat andchamfered approximately 90° included; the chamfer shall extendslightly below the root of the thread and the edge between flat andchamfer may be slightly rounded.

3. LENGTH - The length of the plug shall be measured overall on a lineparallel to the axis.

4. SOCKETS - See Page 13 Table 11, for hexagon socket dimensions.A slight chamfer, radius or countersink on hexagon sockets is permis-sible.

TABLE 20 DIMENSIONS — FLUSH TYPE — 7/8 TAPERD L (3)

NOMINALO.D.

THREADSPERINCH

NOMINALSIZE

J

NOM.

HEX SOCKETSIZE

MIN.

KEYENGAGEMENT

T G

WALLTHICKNESS

MIN. MAX. MIN.

BASICPITCH

DIAMETERAT SOCKET

FACE

OVERALLLENGTH

1/161/81/43/8

1/23/4

0.3070.4010.5290.667

0.8301.041

27271818

1414

5/323/161/45/16

3/89/16

0.1560.1870.2500.312

0.3750.562

5. IDENTIFICATION GROOVES - Six equally spaced identificationgrooves are located equidistant between corners of hexagon socketand edge of chamfer with no particular alignment with hexagon. On1/16 - 27 plugs, three identification grooves are permitted because ofspace limitations.

6. DESIGNATION - Each of the characters in the symbol has a definitesignificance as follows:

P = PlugT = TaperF = Flush

7/8 = .875 inch taper per 12 inches

Applicable Standards and SpecificationsANSI B2.2

0.1400.1400.2180.250

0.3120.312

0.0520.0490.0450.040

0.0670.054

0.2500.2500.4060.406

0.5310.531

0.2350.2350.3910.391

0.5160.516

0.282530.374950.493660.62904

0.781030.99147

24

TABLE 21 HOLO-KROME SOCKET JAM SCREWS

NOMINAL

J

NOM.SOCKET

SIZE

TABLE 21 DIMENSIONS

0.11200.12500.13800.16400.19000.25000.31250.37500.43750.50000.62500.75000.87501.0000

0.0680.0830.0830.0990.1150.1150.1460.1770.2080.2400.3020.3650.4270.490

0.0780.0940.0940.1090.1250.1250.1560.1880.2190.2500.3120.3750.4380.500

0.0880.1030.1030.1190.1350.1350.1660.1970.2280.2600.3220.3850.4470.510

4568

101/4

5/163/8

7/161/25/83/47/81

NOTES FOR TABLE 211. THREADS. Threads are Class 3A UNC or UNF. 2. SOCKETS. See Page 13 Table 11, for hexagon socket dimensions.

TABLE 22 INTERNAL WRENCHING ALLENUTS

0.1870.1870.2570.2800.3070.4030.4980.5900.7100.8000.9861.1581.3611.533

0.1830.1830.2530.2750.3020.3980.4930.5850.7050.7950.9801.1521.3551.527

0.1790.2050.2300.2730.3190.4190.5220.6210.7330.8361.0101.1851.3581.532

0.2050.2050.2740.3020.3310.4250.5210.6150.7380.8361.0341.2091.4241.612

TABLE 22 DIMENSIONS

4568

101/45/163/87/161/25/83/47/81

MAX.

B L

NOMINALNUTSIZE MAX. MIN.

D

MIN.

E

NOM.

F G

MIN. MIN.

MINIMUMCOUNTERBORE

HOLE SIZE(1)

0.1720.1980.2230.2660.3090.4090.5120.6060.7180.8210.9951.1701.3431.517

0.2090.2090.2780.3070.3360.4300.5260.6200.7430.8411.0401.2151.4301.620

1/81/8

5/323/163/161/4

5/163/8

7/161/25/83/47/81

0.0800.0950.1000.1250.1700.2250.2850.3250.3600.4450.5000.6000.7000.810

0.0460.0560.0710.0840.0960.1360.1650.1950.2350.2650.3250.3850.4450.495

0.2020.2020.2700.2980.3270.4210.5160.6100.7330.8311.0281.2031.4181.606

BODY DIAMETER

MIN.MAX.

LENGTH OVERALL KNURL DIAMETER SOCKET SIZE THREAD LENGTH KNURL LENGTH

NOTES FOR TABLE 221. Dimensions given indicate minimum counterbore hole size whereAllenut is to be pressed or drawn into nonhardened material foranchoring purposes.

2. MATERIAL. (a) Alloy Steel hardened by quenching in oil andtempering to HRC 33-39. (b) Steel, corrosion resistant of type 203-EZor equivalent.

3. THREADS. Threads shall be UNC-2B or UNF-2B series in accor-dance with ANSI B1.1 and FED-STD-H28.

4. MECHANICAL PROPERTIES. Product will meet the proof loadrequirements of ASTM A-194 Grade 2H Heavy hex nuts.

There are no reference specifications, as the Allenut represents anoriginal, genuine Allen-designed product.

MAX. MIN.

LENGTH

L

0.0500.0620.0620.0780.0940.1250.1560.1880.2190.2500.3120.3750.5000.562

1/161/165/643/321/8

5/323/167/321/4

5/163/81/2

9/16

BASICSCREW

DIAMETERNOMINAL

SIZE

25

TABLE 23 HOLO-KROME THREAD STANDARDS

NOMINALSIZE

COARSE SERIES

TABLE 23 UNIFIED SERIES CLASS 3A

01234568

101/4

5/163/8

7/161/25/83/47/81

CLASS. Holo-Krome Socket Head Cap Screws through one inch indiameter and all other Holo-Krome standard threaded products are

manufactured to a Class 3A thread fit. Socket Head Cap Screws aboveone inch in diameter are made to Class 2A.

-64564840403232242018161413111098

MAX. MIN. MAX. MIN.

PITCH DIAMETER MAJOR DIAMETERTHREADSPER INCH

UNRC

FINE SERIES

MAX. MIN. MAX. MIN.

PITCH DIAMETER MAJOR DIAMETERTHREADSPER INCH

UNRF

MINIMUMMINORDIAM.

MINIMUMMINORDIAM.

-0.06290.07440.08550.09580.10880.11770.14370.16290.21750.27640.33440.39110.45000.56600.68500.80280.9188

807264564844403632282424202018161412

0.05190.06400.07590.08740.09850.11020.12180.14600.16970.22680.28540.34790.40500.46750.58890.70940.82860.9459

0.05060.06260.07440.08580.09670.10830.11980.14390.16740.22430.28270.34500.40190.46430.58540.70560.82450.9415

0.06000.07300.08600.09900.11200.12500.13800.16400.19000.25000.31250.37500.43750.50000.62500.75000.87501.0000

0.05680.06950.08220.09490.10750.12020.13290.15850.18400.24350.30530.36780.42940.49190.61630.74060.86470.9886

0.04250.05360.06430.07420.08320.09360.10360.12590.14710.20110.25570.31800.36950.43190.54940.66500.77810.8874

RADIUSPITCH(TPI)

80726456484440363228242018

0.00140.00150.00170.00190.00230.00250.00270.00300.00340.00390.00450.00540.0060

0.00180.00200.00230.00260.00300.00330.00360.00400.00450.00520.00600.00720.0080

MIN. MAX.

RADIUSPITCH(TPI)

16141312111098765

4-1/2

0.00680.00770.00830.00900.00980.01080.01200.01350.01550.01800.02170.0241

0.00900.01030.01110.01200.01310.01440.01600.01800.02060.02410.02890.0321

MIN. MAX.

RADIUSED RUNOUT THREADS. To ensure maximum resistance tofatigue, the incomplete or runout threads on all Holo-Krome standardthreaded products where applicable are radiused.

RADIUS ROOT. All Holo-Krome standard socket head cap screws, flathead cap screws, button head cap screws, low head cap screws, andshoulder screws are manufactured to UNR form controlled root radiusthreads for increased fatigue strength. The opposite table illustratesthe radius root limits for the UNR form threads:

Applicable Standards and SpecificationsANSI B1.1 and B1.3

RADIUS ROOT DIMENSIONS

12121212--

UNIFIED SERIES CLASS 2A

1-1/81-1/41-3/81-1/21-3/4

2

77665

4-1/2

1.03001.15501.26431.38931.61741.8528

1.12281.24781.37261.49761.74731.9971

1.02281.14761.25631.38121.60851.8433

1.10641.23141.35441.47941.72681.9751

1.06911.19411.31901.4440

--

.93001.05481.14801.27291.50921.6900

-0.05130.06120.07030.07770.09060.09530.12120.13340.18230.23740.29060.34130.39640.50290.61570.72600.8325

-0.06290.08190.09450.10690.11990.13200.15800.18280.24190.30380.36560.42720.48910.61290.73710.86110.9850

-0.07300.08600.09900.11200.12500.13800.16400.19000.25000.31250.37500.43750.50000.62500.75000.87501.0000

-0.06140.07280.08380.09390.10690.11560.14150.16040.21470.27340.33110.38760.44630.56190.68060.79810.9137

1.06311.18791.31271.4376

--

1.12321.24821.31271.4981

--

1.11181.23681.36171.4867

--

1.00901.13381.25861.3835

--

26

+ Corroded End (anodic, or least noble)

MagnesiumMagnesium AlloysZincAluminumCadmiumIron and Carbon Steel4-6% Cr. Steel (active)Stainless (active) ....................................................Lead-Tin SolderLeadTinNickel (active)Inconel (active)BrassesCopperBronzesCopper-nickel AlloysMonelSilver SolderNickel (passive)Inconel (passive)Stainless (passive) .................................................SilverGraphiteGoldPlatinum

- Protected End (cathodic, or most noble)

TABLE 24 HOLO-KROME FINISHES

FINISH SPECIFICATIONS COATINGS OR SURFACE TREATMENTS

Thermal Black Oxide — Standard heat treatment finish, includes light drying oil

Chemical Black Oxide — Chemical treatment plus rust resistant, non-drying oil

Mil-C-13924 — Same as chemical black oxide except for type of oil used

Air Tempered — Plain, heat treated finish with no oil, suitable for plating

Passivated — Final treatment for stainless steel, QQ-P-35

Phosphate — Zinc phosphate per MIL-P-16232 Type Z Class 3

Phosphate & Oil — Zinc phosphate plus non-drying oil per MIL-P-16232 Type Z Class 2

Phosphate & Oil — Zinc Phosphate plus drying oil per MIL-P-16232 Type Z Class 1

Zinc Plated — Electroplated Zinc per ASTM B 633 Also QQ-Z-325

Cadmium Plated — Electrodeposited Cadmium per ASTM B766 Also QQ-P-416

Endurion — Tin-Zinc Phosphate with drying oil and colored dye as specified.

Electroless Nickel — Nickel plating for wear resistance.

GALVANIC SERIES (IN SEA WATER)

TABLE 24B

EXPANSION OF METALS DUE TO TEMPERATURE

L1 = (L0) (T2-T1) (c)

TABLE 24A

GALVANIC CORROSION

Galvanic corrosion occurs when two dissimilar metals are in contact, in a liquid capable of carrying electric current. Under these conditions the leastnoble metal (the anode) corrodes, while the more noble metal (the cathode) is not attacked.

In general, galvanic corrosion may be avoided by uniformity in types of metals used. If uniformity is not practical, metals should be used which are asclose as possible to each other in the galvanic table below which lists metals in order of increasing nobility.

Stainless steel is “active” when chemicals present do not allow the formation of an oxide film on the surface of the metal. The treatment of stainless ina passivating solution will accelerate the formation of the oxide film, thus making it “passive” and thereby increasing its resistance to galvanic corrosion.

When dissimilar metals are used together, separate them with a dielectric material or coating.

L1 = Increase in length in inches.L0 = Original length, expressed in inches.T2 = the higher temperature, in °F.T1 = the lower temperature, in °F.c = Coefficient of Thermal Expansion, expressed

in inches per inch per Degree Fahrenheit.

{

{

Type 410Type 430Type 302Type 310Type 316

Type 410Type 430Type 302Type 310Type 316

27

MECHANICAL PROPERTIESAND

APPLICATION DATAINCH PRODUCT

28

MECHANICAL PROPERTIES AND APPLICATION DATA

HEADING PRACTICE

Screws from #0 through 1 inch diameter (and the Metric counterparts) arenormally Thermo-Forged® to insure proper grain flow and reduced inter-nal stresses. Sizes over 1 inch diameter are hot formed.

THREADING PRACTICE

Standard Holo-Krome Alloy Steel Socket Head Cap Screws through1-3/4'' in diameter are roll threaded, while thread lengths longer thanstandard or special thread pitches may be rolled or cut. Set Screw threadsmay be rolled, cut or ground.

APPLICATION DATA

Standard Holo-Krome Alloy Steel Socket Products are manufactured toprovide the optimum performance characteristics. The hardness is care-fully controlled, not only to be within specification, but also to provide a partwhich will perform under difficult conditions. Ductility is maximized, toallow both the best possible fatigue life, and the ability to withstand thehighest torquing loads to provide maximum clamping force and preload.

The Thermo-Forging process provides excellent grain-flow through thepart, and, when complemented with the thread rolling process includingradiused root run-out threads, provides optimum fatigue life.

For applications requiring high temperature resistance, corrosion resis-tance and many other special characteristics, special materials can beformed with the same process to provide the same benefits. Requests forspecial parts should be directed to the Holo-Krome Sales Department,and any technical questions or requests for information should be directedto the Holo-Krome Engineering Department.

MECHANICAL REQUIREMENTS

SPECIFICATIONS

Holo-Krome socket products are manufactured in accordance with andtested to meet the requirements of various specifications. In the dimen-sional data pages of this handbook, two specifications are generallylisted. There is an ASME/ANSI B18 document identified for nearly everyproduct, which delineates the dimensional characteristics of the product.In addition, there is an ASTM Specification also identified for eachproduct, from which the mechanical properties and testing requirementsgiven herein are derived.

MATERIALS

Holo-Krome Alloy Steel Socket Products are made from a material whichconsists of a carbon steel to which one or more of the following elementshas been added to provide heat treatment response to insure that thespecified properties are met after the appropriate heat treatment. Thealloying elements may be: chromium, nickel, molybdenum or vanadiumonly. There are various materials used to obtain the necessary properties,but all of them meet the chemical requirements of the specifications, andall are alloy steels.

HEAT TREATMENT PRACTICE

Holo-Krome Alloy Steel Socket Products are hardened and tempered inatmospherically controlled furnaces to meet the requirement of a neutral,through-hardened structure, consisting of tempered martensite. Re-quired minimum tempering temperatures are adhered to, and the prod-ucts meet all of the chemical and physical requirements of the specifica-tions. The atmosphere is controlled to prevent carburization or decarburi-zation as required by the specifications.

29

It is also true that the manufacturing quality of a socket screw is farsuperior to a low-grade hex head. Socket screws have closer tolerancefor better fit and radius root threads for greater reliability under dynamicloading.

Take, for example, a situation where 60,000 lbs. is the design load. Thiswould require (4) 7/8 diameter Grade 2 hex heads, or (15) 3/8 diameterGrade 2 hex heads or (4) 3/8 diameter socket screws. Obviously, thestructure would have to be much larger to accept the 7/8 diameter tappedholes. The cost of the larger drill and tap is approximately 7 times as muchand the power to tap the hole is significantly higher. The socket screwsprovide the lowest cost, most reliable assembly.

On the surface, it may appear as though it is less expensive to purchaseGrade 2 cap screws, than socket screws. Normally, when purchasing capscrews, you are buying holding power. The lowest cost fastener perpound of holding power is a socket screw. The graph below is based onrelative cost data that should remain proportional regardless of the actualfastener cost. It can be seen that the socket screw has the lowest cost perpound of holding power.

Because a socket screw can hold more pounds per size, either fewersocket screws can be used or smaller size screws can be used. In eithercase, the cost of drilling and tapping is greatly reduced and the assemblysize itself can be kept to a minimum. The actual total assembly cost issignificantly lower.

WHY USE A SOCKET SCREW, INSTEAD OF LOW COST GRADE 2 OR GRADE 5 HEX HEAD?

30

APPLICATIONS OF VARIOUS HEAD STYLES

SOCKET HEAD CAP SCREW SOCKET BUTTON HEAD

This screw is designed as a high tensile strength fastener for clampingassemblies against relative movement, parallel to the screw axis.Although its high strength allows machine components to be clampedwith enough force to create a high resistance to lateral movement, thistype of fastener is not meant to resist shear loads. In applications wherehigh shear loading is possible, the assembly should be dowel pinned.

Button head screws are designed for light duty applications such assecuring guards, covers, ornamental fixtures, etc. Button head screwspresent a pleasing appearance to an assembly. Holo-Krome canprovide these screws with a tamper resistant socket.

Flat head screws are used for flush mounting of sections, usually whereone part slides over another or one part is mounted on another. Flathead screws, like button heads and low heads, are limited by configu-ration in their tensile strength capability. Because of this, they shouldnot be used in applications requiring full strength, where Socket HeadCap Screws should be used.

These are high strength, precision fasteners that are designed to beused in applications where head height clearance is a problem.Because of their reduced head height and smaller socket size, theynormally cannot be preloaded as high as a standard socket head capscrew and should not be subjected to high dynamic loads.

SOCKET LOW HEAD SOCKET FLAT HEAD

31

TABLE 25 HOLO-KROME MECHANICAL PROPERTIES SOCKET HEAD CAP SCREWS–1960 SERIES

Standard Holo-Krome Alloy Steel Socket Head Cap Screws are manu-factured from Holo-Krome analysis high grade alloy steel hardened andtempered to provide the following mechanical properties:

ELONGATION*IN 2 INCHES

PER CENT MIN.

0 to 1/2Over 1/2

NOMINALSIZES

180,000170,000

TENSILE STRENGTHpsi MIN.

162,000153,000

YIELD STRENGTHpsi MIN.

810

REDUCTION OF AREA*PER CENT MIN.

3540

3937

MINIMUM HARDNESSROCKWELL C

The materials and heat treatment used for standard Holo-Krome AlloySocket Head Cap Screws were selected to provide products that wouldhave optimum tensile strength, impact strength and fatigue life. Forspecific applications, screws can be supplied to higher hardness levelsso that their tensile strength will exceed values listed. However, suchscrews will have lower ductility, impact strength and fatigue life at higherstress levels than will standard screws.

NOTES FOR TABLE 25The mechanical properties listed are for standard screws tested atnormal room temperatures. In applications where the temperaturesare considerably above or below room temperature the effect of thetemperature on the screw strength must be considered. Short timetensile, creep and stress relaxation should be considered for applica-tions where the temperature exceeds 400°F (204°C). Lower ductility,impact strength and fatigue life must be considered for screws subjectto temperatures below -20°F (-29°C).

0123

4568

101/45/163/8

7/161/25/83/4

7/811-1/41-1/2

UNRC UNRF

STRAIGHTTENSILE STRENGTH

(POUNDS MIN.)

SINGLE SHEAR STRENGTH(POUNDS MIN.)

THREAD SECTION

THREAD STRESSAREA

UNRC UNRF

STRAIGHT YIELDSTRENGTH

(POUNDS MIN.)

UNRC UNRFBODY

SECTION

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.00001.25001.5000

—475665875

1,0901,4301,6402,520

3,1505,7259,430

13,950

19,13525,54038,40056,750

78,500103,000164,700238,800

320500710940

1,1901,4901,8252,650

3,6006,550

10,44015,805

21,36528,78043,50063,400

86,500112,700182,400268,800

—425600790

9751,2901,4702,270

2,8355,1508,490

12,555

17,22022,99034,55051,100

70,70092,700

148,250214,950

290450635845

1,0701,3451,6452,385

3,2405,9009,395

14,225

19,23025,90539,15057,050

77,850101,450164,150241,900

305450625830

1,0601,3251,6152,280

3,0605,2958,285

11,910

16,20021,17531,30045,050

61,35080,100

125,100180,200

—290405535

665875

1,0001,535

1,9203,4955,7508,510

11,65015,56523,45034,650

47,90062,850

100,500145,700

205315445595

750940

1,1501,670

2,2704,1306,5759,950

13,44518,10527,40039,950

54,50071,000

114,900169,300

* The values for elongation and reduction of area apply only to cylindrical test specimens.Values are based on ASTM A-574

UNRC UNRF

0.001800.002780.003940.00523

0.006610.008300.010150.01474

0.02000.03640.05800.0878

0.11870.15990.2560.373

0.5090.6631.0731.581

—0.002630.003700.00487

0.006040.007960.009090.0140

0.01750.03180.05240.0775

0.10630.14190.2260.334

0.4620.6060.9691.405

CAUTION: IMPROPER LOADING OF THESE FASTENERS WILL CAUSE FAILURES

TABLE 25 TENSILE, YIELD AND SHEAR STRENGTH

NOMINALSIZE

BASICSCREW

DIAMETER

32

TABLE 26 HOLO-KROME SOCKET HEAD CAP SCREWS - TORQUE DATA - 1960 SERIES

* These tightening torque values are 75% of the torque required to yield the screw, and apply only for the conditions listed below.Different percentages of torque-to-yield values are also commonly used for special conditions.

NOTES FOR TABLE 26These are average values for standard Holo-Krome 1960 Series AlloySteel Socket Cap Screws with black finish, tested with hardened steelplates, and hardened nuts with the threads and bearing areas lubri-cated with plain, medium viscosity machine oil.

The relationship between the torque and the induced tension (preload)can be expressed by the empirical formula T=KDP, in which T is thetightening torque in inch pounds; D is the nominal diameter of thescrew; P is the tension (in pounds) induced in the screw; and K is thetorque coefficient. The torque coeffiecient is not constant but varieswith the material, surface finish and lubricity of the threads and headbearing area of the screws and parts fastened.

For the conditions shown above (standard alloy steel black finishedscrews clamping hardened steel parts), K will range from 0.19 to 0.25.For cadmium plated screws with steel parts, K will usually fall between0.13 and 0.17. For zinc plated screws K may fall between 0.30 and0.34. When the thread and head bearing surfaces are covered withcertain types of lubricants, or with anti-seize compounds, K can dropas low as 0.05. At the other extreme, combinations of certain materials,such as austenitic stainless steel screws and parts not lubricated orcoated, can result in K values as high as 0.35, or more.

Because the induced tension can vary considerably from one type ofassembly to another for any given torque, the above data should beused with caution — particularly in applications where the control ofpreload is critical and must be obtained by the torque wrench method.For such applications, the relationship between torque and induced

tension should be determined experimentally for the actual parts andlubrication practice involved.

TIGHTENING TORQUES. At the tightening torques listed standardHolo-Krome alloy steel 1960 Series screws, used under the conditionsdescribed, will be preloaded to approximately 75% of the tensioninduced at yield. The bearing stress under the head at these preloadswill be approximately 80,000 psi, so indentation should not occur whenthe parts clamped are of steel or cast iron with a hardness equal to orin excess of Rockwell B 85. With softer materials, washers may berequired under the heads of the screws to avoid indentation.

In applications where screws are subject to fatigue from dynamicloading, the importance of proper preloading during assemblycannot be over-emphasized. The proper preload is especiallyimportant for rigid-type (metal-to-metal) joints, where it has been foundthat the use of a preload greater than the external load will usuallyeliminate the possibility of fatigue failure. For this reason, the preferredpractice for such asemblies is to preload to 75% of the induced tensionat yield.

FOR FLEXIBLE TYPE JOINTS, HOWEVER, AND FOR ASSEMBLIESEXPOSED TO ELEVATED TEMPERATURES, MUCH LOWERPRELOADS MAY BE REQUIRED. No general recommendations arepossible for such assemblies or service conditions. Each applicationmust be analyzed individually, because the preload requirements mayvary considerably from one application to another. Users who desiresuggestions for the preload or tightening torque to be used for a specificapplication are invited to contact Holo-Krome.

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.00001.25001.5000

2.64.88.0

12.0

18.024.034.058.0

90.0230.0460.0845.0

1,305.02,065.03,800.06,750.0

9,200.013,000.027,750.049,000.0

UNRC UNRFUNRC UNRF

0123

4568

101/45/163/8

7/161/25/83/4

7/811-1/41-1/2

—4.57.5

11.0

16.024.030.055.0

79.0200.0415.0740.0

1,190.01,800.03,400.06,000.0

8,250.012,500.025,000.043,500.0

190290410550

690870

1,0701,550

2,1004,0406,4509,770

13,18017,80026,89039,150

45,83059,66296,600

142,280

—280390510

630830950

1,460

1,8403,5305,8208,620

11,83015,76023,74035,080

41,59054,35087,225

126,450

TENSION INDUCED IN SCREWSTORQUED AS RECOMMENDED

(POUNDS)RECOMMENDED TIGHTENING TORQUE

(INCH - POUNDS)*

TORQUE-TENSION TIGHTENING TORQUE DATA

BASICSCREW

DIAMETERNOMINAL

SIZE

33

TABLE 27 DECARBURIZATION AND DISCONTINUITY LIMITS

CARBURIZATION OR DECARBURIZATION

Surface carbon content variations conform to the limits specified inTable 27 when tested in accordance with ASTM A 574. There shouldbe no complete decarburization nor any carburization. Carburization ordecarburization can only be measured accurately on a screw that hasbeen cross sectioned on a plane that is parallel to and passes throughthe screw axis.

When the engineering requirements of the application require thatdecarburization must be more closely controlled, the purchaser shouldspecify the applicable limits in the original inquiry and in the purchaseorder.

DISCONTINUITIES

SOCKET DISCONTINUITIES

Discontinuities in the socket area are allowed to a maximum depth of0.03D or 0.005 inch (whichever is greater), providing they do not affectthe usability and performance of the screw.

Longitudinal discontinuities must not exceed 0.25T in length. Permis-sible and nonpermissible discontinuities are shown in Figure 1.

PERMISSIBLE HEAD AND SHANK DISCONTINUITIES

Discontinuities as defined above are permitted in the locations illus-trated in Figure 1 to the depths described above, with the addition thatperipheral discontinuities are permitted a maximum depth = 0.06D, butnot over 0.064 inch. These discontinuities are permitted providing theydo not affect the usability and performance of the screw. All disconti-nuities are measured perpendicular to the indicated surface.

When the engineering requirements of the application require thatsurface discontinuities must be more closely controlled, the purchasershould specify the applicable limits in the original inquiry and in thepurchase order.

REJECTION

Rejections should be reported to Holo-Krome within 30 days of receiptof the parts, by the purchaser. The rejection may be in writing to thedistributor or directly to the Holo-Krome Sales Department. When nospecial requirments are specified, industry standards such as ASTMA574 will be used as referee documents.

FIG. 1

0.75 H FROMROOT TO

CREST, MIN.

THREADHEIGHT, H

0.1 H ATROOT, MAX.THREADS/IN.

0.0080.0090.0100.011

0.0130.0140.0150.017

0.0190.0220.0260.031

0.0340.0380.0440.047

0.0510.0560.0610.068

0.0770.0880.1020.123

0.1360.153

80726456

48444036

32282420

18161413

1211109

8765

4.54

0.0060.0070.0080.008

0.0100.0110.0110.013

0.0140.0170.0200.023

0.0260.0290.0330.035

0.0380.0420.0460.051

0.0580.0660.0770.092

0.1020.115

0.0010.0010.0010.001

0.0010.0010.0020.002

0.0020.0020.0030.003

0.0030.0040.0040.005

0.0050.0060.0060.007

0.0080.0090.0100.012

0.0140.015

TABLE 27 DECARBURIZATION LIMITS

34

TABLE 28 HOLO-KROME STAINLESS STEEL SOCKET HEAD CAP SCREWS

NOTES FOR TABLE 28Tensile strengths given above are for standard stainless steel sockethead cap screws, 1960 Series tested at room temperatures. Whenscrews are to be exposed to higher temperatures the effect of tempera-ture upon the short time properties and the possiblity of plasticdeformation, or creep, should be considered. At 800°F., the tensilestrength of standard stainless steel screws will be aproximately 75% ofthe room temperature strength, and the screws have good creep

resistance. Normally, standard stainless steel screws are not usedabove 800°F., because above this temperature the material is subjectto intergranular corrosion.

The mechanical properties and torquing data for cap screws made fromstainless steels other than the standard material, or for sizes andlengths not stocked, will be furnished on request.

* Apply only to stock sizes. All other lengths and sizes will have a minimum tensile strength of 80,000 psi.** On specimens onlyValues based on ASTM F837

MATERIALStandard Holo-Krome Stainless Steel Socket Head cap screws aremade from an austenitic (18-8) stainless steel. They withstand allordinary rusting, are immune to all foodstuffs, sterilizing solutions, mostof the inorganic chemicals, dyestuffs and a wide variety of organicchemicals. They resist nitric acid well, halogen acids poorly andsulfuric acids moderately.

Holo-Krome Stainless Steel cap screws are passivated by immersion

in a nitric acid bath subsequent to the last manufacturing operation.This rids the surface of contaminants picked up during fabrication thatcan cause surface staining or rusting.

Holo-Krome standard stainless steel cap screws have low magneticpermeability which makes them suitable for electrical applicationswhere non-magnetic parts are required.

Applicable Standards and SpecificationsASTM F 837

UNRC UNRFUNRC UNRFUNRC UNRF


THREAD SECTION

TENSILE STRENGTH*(POUNDS MIN.)

YIELD STRENGTH**(POUNDS MIN.)

TIGHTENING TORQUEINCH - POUNDS

UNRC UNRF

-250350575

865133016603020

49807360

13500

171265375630

965140019003460

55108340

15200

-79

111181

273420525954

157023254268

-150211344

518798998

1813

298744188088

5483

117198

305442600

1092

174026354800

103159225377

579840

11402075

330650009115

-2.54.06.0

16.030.042.0

100.0

184.0329.0805.0

1.42.64.59.0

18.034.048.0

116.0

203.0371.0910.0

0124

68101/4

5/163/81/2

.0600

.0730

.0860

.1120

.1380

.1640

.1900

.2500

.3125

.3750

.5000

TABLE 28 MECHANICAL PROPERTIES OF THREADED TO THE HEAD STAINLESS STEEL CAP SCREWS

BASICSCREW

DIAMETERNOMINAL

SIZE

35

TABLE 29 HOLO-KROME BUTTON HEAD AND FLAT COUNTERSUNK HEAD SCREWS

Standard Holo-Krome Alloy Steel Button, Flat and Low Head Cap Screwsare manufactured from Holo-Krome analysis high grade alloy steel,hardened and tempered to provide the following mechanical properties.Because of the head configuration, neither button nor flat head socket capscrews can develop the full strength of the raw material heat treatment,

and the values show below for tensile values are minimum strengthswhich full size screws will pull in a tensile test.

Applicable Standards and SpecificationsASTM F835

CAUTION:BUTTON HEAD CAP SCREWS ARE DESIGNED FOR LIGHT FASTENING APPLICATIONS ONLY, SUCH AS SHEETMETALCOVERS, PLASTIC GUARDS, ETC. THEY SHOULD NOT BE USED IN CRITICAL HIGH STRENGTH APPLICATIONS WHERESOCKET HEAD CAP SCREWS SHOULD BE USED.

4568

101/45/163/8

7/161/25/83/4

7/81

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.0000

SHEAR STRENGTH(POUNDS MIN.)

BODY THREADSECTION SECTION

BUTTON HEADS


TENSILE STRENGTH(POUNDS MIN.)


TIGHTENING TORQUE(INCH - POUNDS)

FLAT COUNTERSUNK HEADS


880-

1,3202,030

2,5404,6107,600

11,200

-20,60030,500

-

--

620-940

1,450

1,8103,3005,4308,040

-14,70023,400

-

--

8-1530

65125200360

-10001750

-

--

8801,1501,3202,030

2,5404,6107,600

11,200

15,40020,60030,50045,100

62,40081,800

1,1001,3701,6702,360

3,1805,5008,590

12,350

16,80022,00034,35049,500

61,00080,100

620820940

1,450

1,8103,3005,4308,040

11,00014,70023,40034,600

47,90062,850

9.5141832

75140245400

600120020004000

60008500

TABLE 29 MECHANICAL PROPERTIES AND TIGHTENING TORQUES FOR BUTTON AND FLAT COUNTER-SUNK HEAD CAP SCREWS

NOTES FOR TABLE 29 AND TABLE 29A

The mechanical properties listed are for screws tested and used atnormal room temperatures. The values for the Low Heads are based ona tensile strength of 170,000 psi minimum and a minimum hardnessvalue of HRC38. In applications where the temperatures are considera-

bly below or above room temperature, the effect of the temperature mustbe considered. Short time tensile, creep and relaxation should beconsidered for applications where the temperature exceeds 400°F (204°C).Lower ductility, impact strength and fatigue life must be considered forscrews subject to temperatures below —20°F (—29°C).

4568

101/45/163/8

7/161/25/8

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.6250

8401,1001,2601,940

2,4404,4307,300

10,800

14,80019,80031,500

620820940

1,450

1,8103,3005,4308,040

11,00014,70023,400

5.09.59.5

19.0

3075

150275

425600

1300

0.0501/161/165/64

3/321/8

5/323/16

7/321/4

5/16



HEX KEY SIZETIGHTENING TORQUE(INCH - POUNDS)

LOW HEAD CAP SCREWS

TABLE 29A MECHANICAL PROPERTIES AND TIGHTENING TORQUES FOR LOW HEAD SOCKETHEAD CAP SCREWS

The torque values given are for standard black screws in rigid joints, when torqued with standard keys or bits.

The torque values are based on the effec-tive torque strength of a standard AllenWrench used within its torque capabili-ties. Because of the size of the socket,these products may not be torqued to thefull preload of which they are capable.

The torque values given are for standard black screws in rigid joints, when torqued with standard keys or bits.Values based on ASTM F-835

NOMINALSIZE

BASICSCREW

DIAMETER

BASICSCREW

DIAMETERNOMINAL

SIZE

36

TABLE 30 HOLO-KROME SOCKET SHOULDER SCREWS

TABLE 30 MECHANICAL PROPERTIES

SHOULDER

NOMINALSHOULDERDIAMETER

NOMINALTHREAD

SIZE

THREAD SECTIONTENSILE STRENGTH

(POUNDS MIN.)


THREAD NECK

HEXKEYSIZE

TIGHTENINGTORQUE

(INCH - POUNDS)**

1/45/163/81/2

5/83/41

10 - 241/4 - 20

5/16 - 183/8 - 16

1/2 - 135/8 - 113/4 - 10

2,5404,6107,600

11,240

20,57032,77048,430

1,2502,3403,9705,985

11,14017,80026,800

4,5157,100

10,28018,350

28,78541,51574,000

1/85/323/161/4

5/163/81/2

50125265470

1,1502,0004,000

**It is recommended that tightening torque be limited to these values when screws are to be tightened or loosened with standard keys or bits.

SHOULDER SCREWS

Shoulder screws, commonly referred to as stripper bolts, are used in avariety of applications. In die sets, they can be used as guides for strippersprings. They are used as pivots for linkages, pulleys and sprockets andas hinges.

Holo-Krome socket shoulder screws are made from Holo-Krome analysishigh grade alloy steel. Holo-Krome step grinds the shoulder and rollthread diameter in one operation after heat treatment to assure concen-tricity. The parts are then specially fed into the roll threader to virtuallyeliminate drunken threads and produce Class 3A UNRC threads.

MECHANICAL PROPERTIES

Tensile Strength ........................................................... 140,000 psi minYield Strength .............................................................. 120,000 psi minElongation in 2 inches* ........................................................... 15% minReduction of Area* .................................................................. 45% minHardness ................................................................. 32 Rockwell C min

*Apply to cylindrical test specimens only

37

Holo-Krome is the only company that Thermo-Forges® socket set screws. This provides a deep socket with smooth walls and there are no broachingchips. It is a Holo-Krome test requirement that all standard, alloy steel set screws, of one diameter length or longer, break a properly hardened hex keywhen overtorqued, without damaging the socket.

CUP POINT. The cup point is the most commonly used point style. It isused for the fast permanent or semi-permanent assembly of parts suchas collars, pulleys, gears or bearings on shafting of hardness up to within10 to 15 Rockwell C points of the screw hardness and where the diggingin of the point is not undesirable.

HOLO-KNURL® POINT. The knurled cup point set screw is designed foruse in applications similar to the cup point but has added resistance toloosening under vibratory conditions. The forged counter clockwise knurlprovides a ratchet type of self-locking action usable even with shafting ofhardness up to within 10 to 15 Rockwell C points of the screw hardness.Holo-Knurl set screws as supplied with the Holo-Torc finish have higherholding power than any standard off-the-shelf set screw.

HALF DOG POINT. The half dog point is generally used for the permanentor fixed location of machine parts on parts such as hardened shafting,hollow tubing, or in place of dowels. When spotted, the hole should alwaysbe of the same diameter as the point. The non-standard full dog point isdesigned for similar applications or where a longer point is desired.

CONE POINT. The cone point set screw is used for permanent locationof a machine part to a hardened or soft shaft. The point is frequentlyspotted particularly when used with a hardened shaft. The cone point isalso used as a pivot or hanger point.

OVAL POINT. The oval point is used where frequent adjustments may berequired or where excessive indentation of the shafting or mating part bythe point is not desirable. It may be used in applications where the pointcontacts the shaft or mating part at an angle. The oval point is also usedwith a spot or a circular or longitudinal groove of similar contour as the ovalpoint itself.

FLAT POINT. The flat point is used for frequent relocation of machineparts on shafting with the least amount of deformation to the shaft surface.The flat point is also useful as a backing for a brass or soft metal plug.

HOLO-KROME SOCKET SET SCREWS — ALLOY STEEL — APPLICATION DATA

38

TABLE 31 HOLO-KROME SOCKET SET SCREWS — AXIAL HOLDING POWER

INTRODUCTION. Set screws @ HRC48-52, unlike most other fasteners,are basically compression fasteners. Because studies made of tensionfasteners do not apply and because of the complex nature of this type ofjoint, the holding power of a set screw is more difficult to predict and controlthan the typical cap screw joint. Many variables introduced by a particularapplication may affect the holding power performance of a set screw. It istherefore important for the designer to understand set screw holdingpower and the nature of the variables involved when designing a set screwjoint.

HOLDING POWER. The forces which a set screw assembled joint cantransmit or withstand without relative displacement of the two parts is ameasure of the holding power of the screw. This holding power can bestbe described in terms of the forces acting to cause relative movement

between the assembled parts.

1. AXIAL HOLDING POWER. Using a simple shaft collar application asan illustration, the force acting on the collar to move it along the shaft iscalled the axial force. The ability of the set screw to withstand this forcewithout relative displacement is called its Axial Holding Power. (SeeFigure B.)

2. TORSIONAL HOLDING POWER. Using a shaft pulley or gear applica-tion as an example, the force (F) acting to rotate or slip the pulley aroundthe shaft is frequently called the rotational force. The ability of a set screwto withstand these forces tending to rotate the part on the shaft withoutrelative movement of the two parts is called Torsional Holding Power.(See Figure C.)

AXIAL HOLDING POWER OF CUP POINT AND HOLO-KNURL ™POINT SET SCREWS (ALLOY STEEL)

* The higher axial holding power is due to the excellent lubricity of the Holo-Torc™ finish, which is available on speical order for Holo-Krome screws.

NOTE — The values above have been developed experimentally by assembling steel collars to cold finished steel bars (Rockwell B 80-100) with standardHolo-Krome alloy steel Cup Point Set Screws with the black finish and standard Holo-Knurl Point Set Screws with Holo-Torc Finish. The setscrews were all as long or longer than their nominal diameter. The axial holding power listed above was the average force required to causea 0.005 inch movement of the collar along the shaft after tightening the set screw to the listed torque. For specific applications, values may varyas much as ± 30 percent from values shown.

Giving a cup point a relative holding power of 1, the holding power of a cone point is 1.07, a flat point or dog point 0.92 and an oval point 0.9.For torsional holding power, multiply the axial holding power value by the shaft radius.

HEX KEYSIZE

TIGHTENING TORQUE(INCH — POUNDS) CUP POINT

WITH BLACK FINISH

AXIAL HOLDING POWER(POUNDS)

HOLO-KNURL™WITH HOLO-TORC*

1.12.12.16.0

6.0111123

4094

183317

502750

1,4602,520

5,7508,000

506380

110

140180200365

5501,0001,6002,200

3,0003,7005,6007,500

10,50014,500

7493

115165

210265295540

8101,4702,3503,250

4,4005,4508,250

11,000

15,50021,500

0123

4568

101/45/163/8

7/161/25/83/4

7/81

0.06000.07300.08600.0990

0.11200.12500.13800.1640

0.19000.25000.31250.3750

0.43750.50000.62500.7500

0.87501.0000

0.0280.0350.0350.050

0.0501/161/165/64

3/321/85/323/16

7/321/45/163/8

1/29/16

BASICSCREW

DIAMETERNOMINAL

SIZE

39

The torsional holding power of the set screw in the given application canthen be determined from the following relationship:

T = Fr

Where (T) equals Torsional Holding Power in inch-pounds, (F) equalsAxial Holding Power in pounds and (r) equals shaft radius in inches.

Example: To determine the torsional holding power of a 3/8 diameterHolo-Krome Cup Point Set Screw assembled on a 5/8 inchdiameter shaft, multiply 2200 pounds (the average axialholding power from Table 31) by 5/16 inch. 2200 x 5/16 = 688inch-pounds Torsional Holding Power.

3. VIBRATIONAL HOLDING POWER. Vibrational Holding Power may bedefined as the resistance of a set screw to loosening under vibration ordynamic loading. Holo-Krome has determined, as a result of numerousstudies, that a set screw will not fail or loosen if the peak forces acting onit, whether vibration induced or from external dynamic loads, do notexceed the ultimate axial or torsional holding power values. For the screwto loosen, the compressive stress existing between the point and the firstengaged thread must be relieved as a result of deformation of the shaftingmaterial adjacent to the set screw point or the threads of the collar. Thiscompressive stress creates friction in the mating threads and between thepoint and shaft which lock the set screw. The internally knurled Holo-Knurl® point significantly increases the locking action by trapping upsetshaft material between the forged teeth. The helix angles of the standardthread series are so low that back-off forces created on the set screw itselfby dynamic loading are insignificant compared to the frictional forcesresisting loosening.

Unfortunately, in most cases the actual peak service forces acting uponthe set screw are difficult to determine. If these peak forces are not known,some safety factor to provide a sufficient margin of holding power shouldbe used. In most cases of failure due to vibrational loading investigatedby Holo-Krome, the loosening has been caused by insufficient seatingtorque.

VARIABLES AFFECTING SET SCREW HOLDING POWER. Whencomparing the performance of various set screws or in the design ofcritical set screw assemblies, it is desirable to control as many of thevariables affecting holding power as possible and to evaluate the effectsof those not controlled. Research has disclosed that the following factorsinfluence set screw holding power to varying degrees.

MULTIPLE SET SCREWS

When using more than one set screw the effect of the additional screwdepends on the relative angle between the screws. To determine theapproximate holding power the following equation can be used:

H (200-.42ø)P =

100

Where:P = Holding Power of assembly, lbs.H = Holding Power of one set screw, lbs.ø = Least angle between screws (180° or less), deg.

TIGHTENING OR SEATING TORQUE. Directly affects the axial thrust ofthe screw and therefore the ultimate holding power. The importance ofusing proper tightening torque cannot be overstressed. Because Holo-Krome sockets are Thermo-Forged,® they can be torqued to the keystrength without cracking the socket wall.

POINT CONFIGURATION. Such factors as poorly machined set screwpoints and lack of thread-to-point concentricity can seriously affectholding power. Because Holo-Krome Thermo-Forged set screws havepoints and sockets forged simultaneously with the thread axis, concen-tricity is assured.

THREAD SURFACE LUBRICITY. This important factor is often over-looked in set screw studies. Lack of thread lubricity means increasedthread friction which consumes driving torque. A high degree of surfacelubricity efficiently utilizes driving torque for optimum axial thrust andholding power. The Holo-Torc finish, which is available on special orders,provides excellent thread lubricity for unmatched holding power pluscorrosion resistance equal to plating.

TAPPED HOLE THREAD SURFACE . The same reasons given above forset screw threads also hold true for tapped hole threads.

MATING PART SURFACE FINISH. The surface finish of the mating parts,for example a shaft and collar, is an important consideration. Becausefriction here is a desirable contributor to holding power these surfacesshould have as low a degree of lubricity as possible.

THREAD HELIX ANGLE – NC OR NF. The UNF series set screws,because of their lower helix angle, do provide slightly higher holdingpower.

ALIGNMENT OF TAPPED HOLE WITH SHAFT. Any deviation betweenthe axis of the set screw and the axis of the shaft decreases the amountof axial thrust that the screw can develop against the shaft and thereforereduces holding power.

OTHERS. Several other influencing factors may become important incertain applications and are worth attention. These are length of threadengagement, yield strength and thickness of collar or ring material, fitbetween shaft and collar, bearing yield strength of shaft material andnature of expected service loads.

40


Standard Allen Wrenches and Bits are manufactured from Holo-KromeAlloy Steel, hardened by quenching in oil from the hardening temperature

and tempered to a minimum hardness of HRC 45 at the surface to providethe following torsional properties:

TORSIONALSHEAR

AVERAGE(INCH-POUNDS)

TORQUERATING

(INCH-POUNDS)

NOMINALKEY OR BIT

SIZE

NOMINALKEY OR BIT

SIZE

CAP SCREWS1960 SERIES

FLATCOUNTERSUNK

HEADCAP SCREWS

BUTTONHEAD

CAP SCREWS

SHOULDERSCREWS

SETSCREWS

PRESSUREPLUGS

0.0280.0350.0501/16

5/643/327/641/8

9/645/323/167/32

1/45/163/87/16

1/29/165/83/4

7/81

1.12.36.5

11.9

25.043.068.098.0

146.0195.0342.0535.0

770.01,600.02,500.04,500.0

6,300.08,750.0

12,000.019,500.0

29,000.043,500.0

——01

2 & 34 & 5

6—

8101/4—

5/163/8

7/16 & 1/2—

5/8—3/4

7/8 & 1

1-1/8 & 1-1/41-3/8 & 1-1/2

—0

1 & 23 & 4

5 & 68—10

—1/45/163/8

7/161/25/8—

3/47/81

1-1/8

1-1/4 & 1-3/81-1/2

—0

1 & 23 & 4

5 & 68—10

—1/4

5/163/8

—1/25/8—

————

——

————

———1/4

—5/163/8—

1/25/83/4—

1—

1-1/4—

1-1/21-3/4

01 & 23 & 45 & 6

810—1/4

—5/163/8

7/16

1/25/83/4—

7/81 & 1-1/8

1-1/4 & 1-3/81-1/2

—1-3/4 & 2

————

————

—1/161/8—

1/43/81/2—

—3/41

1-1/4

—1-1/2, 2

NOTES FOR TABLE 32

TORSIONAL SHEAR STRENGTH. The average torsional shear strengthtabulated above is the average maximum torque which standard keys andbits will transmit when tested to destruction. When so tested, failureshould occur by a clean, square shear fracture.

TORQUE RATING. Standard Allen Wrenches cut into bits for use intorque wrenches will transmit the above torques.

These torque values are the average torque required to develop apermanent visible twist of not more than 10° in bits which have one inchof hexagon exposed between the torque wrench and the socket. Theseare also the torque values which keys transmit when the short arm isinserted in a socket and the long arm is deflected or bent through an angleof 25 to 30° by the application of force near the end of the long arm. Theseare the torque ratings from Federal Specification GGG-K-275D, Amend.1.

TABLE 32 ALLEN WRENCHES AND BITS

NOMINAL SCREW SIZES

TABLE 32MECHANICAL PROPERTIES ALLEN WRENCHES APPLICATION DATA

0.91.85.3

10.3

20.035.055.082.0

118.0160.0278.0440.0

655.01,275.02,200.03,500.0

5,200.06,500.09,000.0

15,500.0

24,600.028,800.0

0.0280.0350.050

1/16 0.062

5/64 0.0783/32 0.0947/64 0.1091/8 0.125

9/64 0.1415/32 0.1563/16 0.1887/32 0.219

1/4 0.2505/16 0.3123/8 0.3757/16 0.438

1/2 0.5009/16 0.5625/8 0.6253/4 0.750

7/8 0.8751 1.000

41

TABLE 33 HOLO-KROME PRESSURE PLUGS

NOMINALSIZE

1/161/81/43/8

1/23/411-1/4

1-1/22


TAP DRILL SIZE

WITH USE OF REAMER WITHOUT USE OF REAMER

-21/6427/649/16

11/1657/641-1/8

1-15/32

1-45/64-

0.2340.3280.4220.562

0.6880.8911.1251.469

1.703-

--

7/1637/64

45/6459/64

1-5/321-1/2

1-47/64-

0.2460.3390.4380.578

0.7030.9221.1561.500

1.734-

120200480960

1440240033604320

55206800

SUGGESTED TWIST DRILL DIAMETERS FOR DRILLED HOLESIZES FOR DRYSEAL PIPE THREADS

The drill diameters given are for tapered internal pipe threads and willusually permit the tapping of acceptable threads in free-machiningbrass or steel provided the drill is correctly sharpened. When hardmetals or other similar materials are to be drilled and tapped, it may benecessary to use a drill of slightly smaller diameter whereas softmaterials may require a larger size.

Tapered pipe threads of improved quality are obtained when the holesare taper reamed after drilling and before tapping. Standard taper pipereamers are used. As in drilling, the actual size of the hole dependsupon the material and is best determined by trial.

TABLE 33 APPLICATION DATA

THREADSPER INCH

27271818

1414

11-1/211-1/2

11-1/211-1/2

HEX KEYSIZE

5/323/161/45/16

3/89/165/83/4

11

PRESSURE PLUGS

Holo-Krome standard pressure plugs are made from high grade alloysteel, hardened and tempered to a through hardness of HRC 36-43.Since the plugs are Thermo-Forged® and roll threaded, they areinherently stronger and do not have broaching chips.

Two basic plug styles are standard with Holo-Krome. These are the3/4 taper, designated NPTF, and the 7/8 taper, designated PTF. Bothtypes have dry seal threads and both should be used in NPTF, 3/4 tapertapped holes.

The 3/4 taper plug is a longer plug and is the one most commonly used.It will work in tapped holes that are not accurately tapped.

The 7/8 taper plug has more closely controlled threads and is designedto be flush with the top of the tapped hole. The thread tolerances arecloser than on the 3/4 taper plugs.

42

HOLO-KROME COATED PRESSURE PLUGS

For problem applications Holo-Krome can supply 7/8 taper plugs witheither the exclusive Holo-Krome Holo-Seal® finish or with Teflon® typecoating.

Holo-Krome has done extensive testing to find the best type ofFluorocarbon (Teflon®) coating available for the plugs. Since this is anongoing study there will probably be periodic improvements to thecoating. The coating criteria are lubricity, corrosion resistance, chemi-cal inertness and heat resistance. Although Fluorocarbon coatedplugs have been tested in the Holo-Krome laboratory to 15,000 psi,their ability to withstand service pressures depends entirely on theapplication parameters.

Fluorocarbon Type:

Low Coefficient of friction 0.05 - 0.07.

Resistant to corrosion, abrasion.

Resistant to oils, alcohols, dilute acids, common solvents.

Dry and clean.

Service temperature to 300°F (150°C)

Holo-Seal® was developed to be used as a substitute for Teflon. It wasdeveloped initially for applications where the lubricity of the Teflonallowed the plug to damage the tapped hole. Because of its lower costand excellent sealing characteristics it is usually preferred to Teflon.

The application advantages of either type of coated plug over tappingand applying gunk to the threads is obvious. When inplace cost or costto replace leaking plugs is considered, precoated plugs are usually theleast expensive alternative.

Holo-Seal Type:

Coefficient of friction equal to plain black plug.

Resistant to oil, dilute acids, many common solvents.

Dry and clean.

Service temperature to 300°F (150°C).

Can withstand hydraulic pressures to 10,000 psi.

HOLO-KROME COATED PLUG PROPERTIES

43

TABLE 34 HOLO-KROME DOWEL PINS


Standard Holo-Krome Dowel Pins are manufactured from Holo-Kromeanalysis High Grade Alloy Steels heat treated to a core hardness ofHRC 47-58 for toughness and strength and a surface hardness of HRC60 minimum for wear resistance. Case depth to be 0.020" min.

CAUTION: Holo-Krome recommends dowel pins be inserted byapplication of a constant pressure, with the pin being shielded incase of fracture. A striking force can cause the pin to shatter.

1/83/161/45/16

3/87/161/25/8

3/47/81

RECOMMENDED HOLE SIZEFOR STANDARD PINS

MAX. MIN.

SINGLE SHEARSTRENGTH(POUNDS)

NOMINALSIZE

DOUBLE SHEARSTRENGTH(POUNDS)

1,8404,1507,360

11,500

16,55022,55029,45046,000

66,20090,200

117,800

3,6808,300

14,72023,000

33,10045,10058,90092,000

132,400180,400235,600

0.12500.18750.25000.3125

0.37500.43750.50000.6250

0.75000.87501.0000

0.12450.18700.24950.3120

0.37450.43700.49950.6245

0.74450.87450.9995

TABLE 34 HOLO-KROME DOWEL PINS MECHANICALPROPERTIES

44

The Nylok Corporation is the originator of the NYLOK (R) process, bywhich any threaded part can be made self-locking. The Nylok self-lockingmethod consists of a nylon patch, strip or pellet, permanently bonded ontoor embedded into the threads of any fastener.

Whether your application requires patch, pellet or strip, this methodprovides a degree of holding power not otherwise possible. The principleis the same for all three types. When mating threads are engaged, thetough, resilient nylon element is compressed, and, with all of the clear-ances thereby closed, a strong counterforce is established, which createsa metal-to-metal contact, which not only locks, but also gives sealingproperties and sets up a positive resistance to vibration.

The nylon element has a strong memory, and will return to its originalshape after removal, providing an excellent degree of re-usability for thesystem. It retains its high strength properties at temperatures up to 250°F, and is virtually unaffected by alcohol, gasoline, caustic soda, and mostcommercial solvents. This element can be added to standard parts, orbuilt into any special fasteners when needed. Holo-Krome Engineers willbe happy to recommend the proper locking method for any specificapplication, based on such factors as type of material, complexity of theparts, hardness, wall thickness, etc. Please contact the Holo-KromeEngineering department for assistance in adapting the Nylok self-lockingfastening method to your application.

RECOMMENDATIONS FOR PROPER APPLICATION OF HOLO-KROME NYLON INSERT SOCKET SCREWS

The Basic Function of the Holo-Krome Nylon-modified self-locking screwis to induce greater friction between the mating external and internalthreads, thereby providing a self-locking holding action. It is, therefore,extremely important to convey the fact that the internal mating thread hasa direct effect on the function of the induced locking torque and reusabilityof the screw and, if improperly tapped, can actually cause failure of theself-locking element. For most effective performance the following pre-cautions and suggestions should be observed, and recommendations asnoted herein should be followed:

1. To provide proper entry of the modified screw into the internal threadand to prevent possible shearing of the nylon before thread engagement,

the leading edge of the internal thread should be countersunk approxi-mately 90° x 1/32" in diameter larger than the thread major diameter.

2. The clearance hole (when required) for the shank of the screw shouldbe at least 0.015 larger than the thread major diameter to allow themodified screw to pass through freely. (See page 51 for recommendeddrill size for shank.)

3. To assure complete utilization of the tensile strength of the screw, theself-locking area should be engaged at least two full threads beyond thestarting thread of the tapped hole.

4. The mating internal thread should be clean and smooth. Sharp threadburrs (from improper tapping, etc.) may reduce reusability of the screw bytearing or shearing the nylon.

5. The internal thread should be within Class 2B or 3B limits. Within theselimits, the greater the percentage of full thread, the higher the self-lockingtorque attained. However, the percentage of full thread appears to havelittle effect on the limits of reusability. Therefore, a variation in torque canbe attained by increasing or decreasing the tap drill size. Best results havebeen attained by using a tap drill size which results in a 75% to 83% fullthread.

6. Since increased friction is the main function of the Nylon modification,and lubrication reduces friction, the presence of a lubricant in theassembly will tend to reduce the self-locking torque. (A short air blast isusually sufficient to remove excessive lubrication before assembly.

7. When using Nylon modified screws in soft materials other than steel(aluminum, brass, etc.) where the normal induced torque may causedamage to the internal threads, it is advisable to reduce the percentageof full thread of the internal member. If the torque still remains too high, itis recommended that the Holo-Krome Engineering Department be con-sulted relative to special pelleting dimensions to meet requirements.

8. An excessive out-of-round condition of the internal thread will causeerratic induced torque and can lead to reduced holding power andreusability. This condition is easily noticeable by high-low torque readingsapproximately 90° apart.

HOW NYLON ELEMENTS LOCK

The locking element is a tough, resilient nylon coating (A) permanentlyapplied to a section of the thread. As the screw is inserted, the matingthreads are forced tightly together. A wedging action is created which setsup a strong lateral counterthrust, locking the threads at (B) opposite thecoating in a strong metal-to-metal grip. Locking occurs whether the screwis seated or not.

HOLO-KROME NYLOK ® HEX-SOCKET SCREWS

45

0

0.75

1.5*

0.5*

INITIALINSTALLATION

(MAX.)

THREADSIZE

FIRSTREMOVAL

(MIN.)

FIFTHREMOVAL

(MIN.)

2

2

3*

1.5*

6

8

2

1

4

5

1

.5

8

12

2.5

1.5

10

18

3

2

1/4

40

5

3

5/16

85

8

5

3/8

110

14

9

7/16

150

20

12

1/2

220

26

16

9/16

270

35

22

5/8

350

45

30

3/4

460

60

45

7/8

700

95

65

1"

900

130

85

•Torque values in inch ouncesTorque values in inch pounds

PREVAILING TORQUE PER IFI-124 (EXTERNAL THREADS) inch - pounds exc. as noted

MAXIMUMTORQUE

INSTALLATION OR REMOVAL

PREVAILING TORQUE PERFORMANCE PER MIL-F-18240 (EXTERNAL THREADS) (inch - pounds)

THREAD SIZE

MINIMUMBREAKAWAY TORQUE

15 REMOVALS

4

3

0.5

6

6

1.0

8

9

1.5

10

13

2.0

1/4

30

3.5

5/16

60

6.5

3/8

80

9.5

7/16

100

14

1/2

110

18

5/8

300

32

NYLON MODIFIED FASTENERS have been tested and approved tomeet the standards of Specification MIL-F-18240 and are approved foraircraft and aerospace use. No need for cross-drilling, lock wiring, etc.

Hex Socket Hex Socket Hex SocketSet Screw Set Screw Set ScrewCup Point Flat Point Cone Point

MS 18063 (steel) MS 18065 (steel) MS 18067 (steel)MS 18064 (cres) MS 18066 (cres) MS 18068 (cres)

HOLO-KROME NYLOK ®* HEX-SOCKET SCREWS

46

TABLE 35

FASTENER RELATED STANDARDS

ANSI or ASME/ANSI

B1.1 Unified Inch Screw Threads (UN and UNR Thread Form)B1.2 Gages and Gaging for Unified Screw ThreadsB1.3 Screw Thread Gaging SystemsB1.7 Nomenclature, Definitions, and Letter Symbols for Screw ThreadsB18.3 Socket Cap, Shoulder and Set ScrewsB18.8.2 Machine Pins (Dowel, Taper, Grooved)B18.12 Glossary of Terms for Mechanical FastenersB18.13 Screw and Washer Assemblies-SemsB18.21.1 Lock WashersB18.22.1 Plain WashersB18.23.1 Beveled WashersB1.20.3 Dryseal Pipe Threads (Inch)B2.1 Pipe Threads (Except Dryseal)B2.2 Dryseal Pipe Threads

ASTM

A574 Alloy Steel Socket Head Cap ScrewsF837 Stainless Steel Socket Head Cap ScrewsF835 Alloy Steel Button Head and Flat Head Cap ScrewsF879 Stainless Steel Button Head and Flat Head Cap ScrewsF912 Alloy Steel Set ScrewsF880 Stainless Steel Set Screws

FEDERAL

FF-S-86 Socket Head Cap ScrewsFF-S-200 Set Screws, Hexagon and Spline Socket, HeadlessGGG-K-275 Wrench, Hexagon, Spline and Square (with Amend. 1)QQ-P-35 Passivation Treatment for Austenitic, Ferritic & Martensitic Corrosion-Resisting SteelQQ-P-416 Plating, Cadmium (Electrodeposited)QQ-Z-325 Zinc Plating (Electrodeposited)GGG-W-641 Wrench, Socket, (and socket handles, and attachments for socket wrenches: hand)

47

TABLE 35 (continued)

MILITARY

MIL-P-21143 Pins Straight, Headless (Dowel)MIL-S-21472 Screw Shoulder, Hexagon Socket HeadMS-16555 Pin, Dowel, Hardened & Ground (Standard Diameter)MS-16556 Pin, Dowel, Hardened & Ground (Oversized Diameter)MS-16995 Screw, Cap, Socket Head, Stainless Steel, UNCMS-16996 Screw, Cap, Socket Head, Stainless Steel, UNFMS-16997 Screw, Cap, Socket Head, Alloy Steel, UNCMS-16998 Screw, Cap, Socket Head, Alloy Steel, UNF

MS-24677, Screw, Cap, Socket Head, Hexagon Drilled Alloy Steel, UNCMS-24678 Screw, Cap, Socket Head, Hexagon Drilled Alloy Steel, UNF

MS-24667, Screw, Cap, Socket Head Flat Countersunk 82° Cad PlatedMS-24671 Screw, Cap, Socket Head Flat Countersunk 82° CRESMS-24673 Screw, Cap, Socket Head, Stainless Steel, Cross Drilled, UNFMS-24674 Screw, Cap, Socked Head, Stainless Steel, Cross Drilled, UNC

MS-51963, Set-Screw - - Hexagon Socket, Cup Point, Cad. Plated, UNCMS-51964 Set-Screw - - Hexagon Socket, Cup Point, Cad. Plated, UNF

MS-51965, Set-Screw - - Hexagon Socket, Flat Point, Cad. Plated, UNCMS-51966 Set-Screw - - Hexagon Socket, Flat Point, Cad. Plated, UNF

MS-51973, Set-Screw - - Hexagon Socket, Cone Point, Cad. Plated, UNCMS-51974 Set-Screw - - Hexagon Socket, Cone Point, Cad. Plated, UNF

MS-51976, Set-Screw - - Hexagon Socket, Half Dog Point, UNCMS-51977 Set-Screw - - Hexagon Socket, Half Dog Point, UNF

MS-51981, Set-Screw - - Hexagon Socket, Oval Point, UNCMS-51982 Set-Screw - - Hexagon Socket, Oval Point, UNF

MS-51053 Set-Screw, Fluted Socket, Alloy Steel, Cad. Plated NC-3AMS-51975 Screw, Shoulder-Socket Head, Hexagon, Alloy Steel, Cad. Plated UNC-3A

MIL-S-7742B Screw Threads, Standard, Optimum Selected Series: General Spec. forMIL-S-8879A Screw Threads, Controlled Radius Root with Increased Minor Diameter, General Spec. forMIL-C-13924 Coating, Oxide, Black for Ferrous MetalsMIL-P-16232 Phosphate Coatings, Heavy, Manganese or Zinc Base (For Ferrous Metals)MIL-F-18240 Fastener, Externally Threaded, 250° Self-Locking Element for

A.I.A.

NAS1351 Screw Cap Socket Head, UNFNAS1352 Screw Cap Socket Head, UNC

48

APPENDIXGENERAL APPLICATION DATA

Page

GLOSSARY OF TERMS ..............................................................................49

TAPPING INFORMATION ............................................................................51

FASTENER JOINT DESIGN ........................................................................52

FASTENER STRENGTHS ........................................................................... 53

HARDNESS CONVERSIONS ......................................................................55

EFFECTS OF ALLOYING ELEMENTS ........................................................ 56

49

GLOSSARY OF TERMS

Tensile Strength - Force or stress required to break a fastener when pulledin straight tension. When expressed as a force, lbs., it applies to a specificsize part. Expressed as a stress, psi, means the force is applied over aspecific area and it could apply to a range of sizes. For example, socketscrews from #0 to 1/2 inch can withstand an applied stress of 180,000 psi.

Stress Area - Theoretical area in the thread section of a fastener over whichthe load is applied.

Yield Strength - This is the measure of the resistance of a material to plastic(permanent) deformation. It is usually at a point of 0.2% permanent strain.

Torsion - Twisting force applied to a fastener during tightening.

Elongation - longitudinal stretching of a fastener caused by a tensile loaddue either to tightening or to the external load.

Shear Strength - the resistance of a fastener to transverse loading. Thistype of load should only be applied to a dowel pin or the unthreaded sectionof a screw.

Rockwell Hardness - One method of measuring hardness of a metal,generally related to the material tensile strength. Normally stated as “C”scale readings, but may be taken as “A”, 30N or 15N scale readings whenlimited penetration is desired. Limited penetration is required when check-ing case hardness or thin parts.

Creep Strength - At elevated temperatures metal under stress elongates.This elongation increases with time and temperature. To prevent failure itis often necessary to change to heat resistant materials.

Fatigue Strength - Under variations in applied stress a fastener feelsinternal stretching that can cause rupture after a specific number of cycles.The number of cycles to failure for a specific load is the fatigue life of thescrew. In rigid assemblies preloading above the external load shouldeliminate fatigue failure.

50

Seams - Inherent discontinuities in raw materials that run longitudinally.They are folds in the material, not fractures at the grain boundary.

Cracks - Fractures passing through or across grain boundaries without theinclusion of foreign elements.

Shank - Portion of a fastener between the head and point.

Body - The unthreaded section between the head and threads.

Fillet - Concave junction between the head and shank.

Bearing Surface - Supporting or locating surface of a fastener with respectto the part which it fastens.

Pressure Flanks - Flank of thread that faces the head of the fastener andwhich applies the load to the internal threads.

Runout Threads -The thread section that is between the full thread and thefillet or body. Holo-Krome specifies special dies to produce a large radiusin this area thus increasing fatigue life.

Standard Fastener - Product represented by standardized dimensions.

Stock Fasteners - Product commercially available at the distribution level.See Holo-Krome’s current catalog for stock sizes.

GLOSSARY OF TERMS

Major Diameter - Largest dia- Minor Diameter - Smallest Dia-meter of the thread. meter of a thread.

Pitch Diameter - Theoretical Root - The base of the Vdiameter at which the thread thread. Holo-Krome producesand thread space are of equal parts with radiused rootthickness. threads.

51

TAPPING HINTS

There are two basic factors to consider in tapped hole strength and cost.These are hole depth and tap drill diameters. The deeper the hole thegreater the tapping time and tool breakage. The smaller the tap drilldiameter the greater the power required to tap and the higher the tapbreakage.

Generally the following minimum engagement lengths are used.

Hardened Steel - 1 diameter

Soft Steel-Cast Iron - 1.5 diameters

Aluminum-Plastic - 2 diameters

These values vary slightly depending on the percent thread tapped.

TABLE A-1 COMMON TAP DRILL SIZES

INCH METRIC

DRILLING DEPTHS FOR TAPPING BLIND HOLESThe minimum depth of a drilled hole for tapping equals the full threaddepth plus the number of turns P (pitch) for each style and size of tap.

UNC UNF DRILLDIAMETER (IN.) WIRE,LETTER,

PITCH (TPI) DEC. FRACTIONAL

#0 80 0.0465 #56

#1 64 0.0595 #5372 0.0595 #53

#2 56 0.070 #5064 0.070 #50

#3 48 0.0785 #4756 0.082 #45

#4 40 0.0890 #4348 0.0935 #42

#5 40 0.1015 #3844 0.1040 #37

#6 32 0.1065 #3640 0.1130 #33

#8 32 0.1360 #2936 0.1360 #29

#10 24 0.1495 #2532 0.1590 #21

0.250 20 0.2040 #628 0.2187 7/32

0.3125 18 0.261 G24 0.272 I

0.375 16 0.313 5/1624 0.332 Q

0.4375 14 0.3680 U20 0.3906 25/64

0.500 13 0.4219 27/6420 0.4531 29/64

0.5625 12 0.4847 31/6418 0.512 13mm

0.625 11 0.5469 35/6418 0.5781 37/64

0.750 10 0.6562 21/3216 0.6875 11/16

0.875 9 0.7656 49/6414 0.8125 13/16

1.000 8 0.875 7/812 0.9129 59/64

1.250 7 1.1094 1-7/6412 1.1719 1-11/64

1.500 6 1.3437 1-11/3212 1.4219 1-27/64

M1.6 0.35 1.25

M2 0.4 1.6

M2.5 0.45 2.05

M3 0.5 2.5

M4 0.7 3.3

M5 0.8 4.2

M6 1.0 5.0

M8 1.25 6.7

M10 1.5 8.5

M12 1.75 10.2

M14 2.0 12.0

M16 2.0 14.0

M20 2.5 17.5

M24 3.0 21.0

M30 3.5 26.5

M36 4.0 32.0

M42 4.5 27.5

DIAMETER THREAD DRILLPITCH (MM)

52

FASTENER JOINT DESIGN

In applications which experience high cyclic loading analysis ofthe fastener loading is critical. Based on the relative stiffness of theassembly and the screw, and the external load applied, the fastener sizeand proper preload can be determined.

Preload is normally achieved by tightening the screw. Thetorque required to achieve the specific preload depends on the surfacelubricity at the threads and at the head, the surface finish, thread pitch, headbearing configuration, and torque wrench accuracy.

PRELOAD AND EXTERNAL LOAD CONSIDERATIONS

When a fastener is tightened, the load on the assembly andfastener increase. In the ideal case, the screw stretches, and the jointcompresses, within the elastic limit, according to Hooke's Law.

Suppose a joint has been tightened to a preload Pi and additionalload, Pe, tending to separate the members is applied. In general in rigidassemblies, as long as the external load is less then Pt it primarilydecompresses the joint and has little effect on the tension in the screw.Thus even if such a load is repeatedly applied, the fastener will not fail infatigue. However, if a repeated external load greater than Pi must beapplied, it should be kept to a minimum, since it produces cyclic tensioningin the screw and may lead to fatigue failure.

This principle has important practical applications. Often whenfasteners fail, the solution used is to switch to the next larger size. Thisinvolves changing the tooling for hole preparation and tightening, andpossibly changing assembly fixtures. Most likely, merely tightening thefastener above the external load would solve the problem. For instance,a 180,000 psi tensile strength socket screw has an average endurance limitof only 15,000 psi. This means that the fastener is capable of withstandinga maximum one-time applied stress of 180,000 psi, but that a stresschange felt by the fastener of more than 15,000 psi could result in a fatiguefailure within a given number of cycles.

A conservative formula giving the tension on a fastener whichhas an external load, Pe is:

Nomenclature

Pt = Total Bolt load, lb.

Pi = Preload, lb.

Pe = External load, lb.

Ks = Screw spring constant, lb./inch.

Kc = Assembly spring constant, lb./inch.

The spring constant, K, for a member is given by:

(area, sq. in.) (modulus of elasticity, psi)

(length, in.)

Since these calculations ignore factors such as bending, heat,and impact loading, they are useful as a guide only.

Torque to achieve preload

When screws are torqued to achieve preload, the torsionalstresses on them reduces the total tensile force they can withstandbefore yielding. The following formula can be used to determine theeffect of this torsional component:

The desired tightening torque can be estimated using theempirical formula:

Pt = Pi + Ks + Kc Pe

Ks[ ]

T = KDP

√ 2 JAP

AP

St = ± ( ) +( )t x r22

Nomenclature

St = Total tensile stress felt by bolt, psi

P = Preload exerted by bolt, lb.

A = Thread stress area, sq. inches

T = Tightening torque, in.-lb.

t = Torsion felt by screw (approximately 40% of applied

torque, depending on lubricity), in.-lb.

r = √A/π

J = πr4 (polar moment of inertia), in.4

K = Constant from 0.05 to 0.35, dimensionless

D = Nominal screw diameter, inches

The constant, K, is normally from 0.19 to 0.25 for a black screw.For a lubricated fastener or one with cadmium plating, K is from 0.13 to0.17. Zinc plated screws, not lubricated, may have a K value as high as0.30 to 0.35.

For rigid parts of steel, the conservative practice is to tighten thefasteners to 75% of yield. Lower torques should be considered forflexible joints, joints with gaskets, or assemblies subject to hightemperatures.

Joint Design Steps

1. Calculate the assembly service load.

2. Determine relative loading on each fastener.

3. Determine the style fastener desired (hex, socket, etc.).

4. Using the highest loaded fastener in assembly, apply an appropriatesafety factory based on the estimated reliability of the service loadvalue, the quality level of the type fastener used, estimate ofassembly techniques consistency, and danger of an assemblyfailure. Normally a safety factory could range from 1.5 to 6.

5. Determine fastener size, tightening torque, and cycle life, whereapplicable.

6. Specify tightening torques on drawing.

Fastener Assembly Tips:

1. Preload properly.2. Do not use split type lock washers on socket head screws or Grade

8 hex screws.3. Use long screws when possible.

4. Avoid transverse or shear loading against the threads.

5. Keep the members clean during assembly.

6. Use wrenches that fit properly and are correctly heat treated.

2

53

*NOTE:Socket Head Cap Screws of Property Class 12.9 are comparable (177 ksi vs. 180 ksi) to the USA standard. However, in Europe particularly, andelsewhere, they may be made in Classes 5.8, 8.8, or 10.9, all of which are significantly weaker than the 12.9. It is critical that any replacement SocketHead Cap Screws be of equal strength to those removed. Beware of substitutions of a lower grade which could lead to catastrophic failure.

TABLE A2 FASTENER STRENGTHS

Fasteners are marked to indicate various strength levels to which whey are manufactured. They are also required to have manufacturer's identificationmarks.

TABLE A2 FASTENER STRENGTHSINCH

IDENTIFICATION SPECIFICATION FASTENER MATERIAL NOMINAL SIZE PROOF YIELD TENSILE GRADE MARK DESCRIPTION RANGE (IN.) LOAD STRENGTH STRENGTH

(psi) MIN. (psi) MIN. (psi)

Grade 2

Grade 5

Grade 8

Socket Screw

Bolts,Screws,Studs

Bolts,Screws,Studs

Bolts,Screws,Studs

Socket HeadCap Screws

Low or MediumCarbon Steel

Medium CarbonSteel Quenchedand Tempered

Medium CarbonAlloy Steel.

Quenched andTempered

Alloy Steel.Quenched and

Tempered

1/4 through 3/4Over 3/4 to 1-1/2

1/4 through 1Over 1 through 1-1/2Over 1-1/2 through 3

1/4 through 1-1/2

#0 through 1/2Over 1/2 through 2

55,00033,000

85,00074,00055,000

120,000

57,00036,000

92,00081,00058,000

130,000

162,000153,000

74,000 60,000

120,000105,000 90,000

150,000

180,000170,000


X = MANUFACTURER'S MARK

METRIC

IDENTIFICATION SPECIFICATION FASTENER MATERIAL GRADE MARK DESCRIPTION PROOF LOAD YEILD STRENGTH TENSILE STRENGTH

Class 5.8

Class 8.8

Class 10.9

Class 12.9

Bolts,Screws,Studs

Bolts,Screws,Studs

Bolts,Screws,Studs

Socket HeadCap Screws*

Low or MediumCarbon Steel

Medium CarbonSteel Quenchedand Tempered

Medium CarbonAlloy Steel.

Quenched andTempered

Alloy Steel.Quenched and

Tempered

380

600

830

970

420

640

940

1100

520(75,900 psi)

830(120,000 psi)

1040(150,000 psi)

1220(177,000 psi)


X = MANUFACTURER'S MARK

MIN. (MPa)

54

METRIC CONVERSIONS

TABLE A3 CONVERSION TABLEFractional Inch to Decimal Inch and Millimeters

MILL-METERS

DECIMALINCH

MILL-METERS

DECIMALINCH

FRAC-TIONAL

INCH

1/641/323/641/16

5/643/327/641/8

9/645/3211/643/16

13/647/3215/641/4

17/649/3219/645/16

21/6411/3223/643/8

25/6413/3227/647/16

29/6415/3231/641/2

13.096913.493713.890614.2875

14.684415.081215.478115.8750

16.271916.668717.065617.4625

17.859418.256218.653119.0500

19.446919.843720.240620.6375

21.034421.431221.828122.2250

22.621923.018723.415624.8125

24.209424.606225.003125.4000

0.5156250.531250.5468750.5625

0.5781250.593750.6093750.625

0.6406250.656250.6718750.6875

0.7031250.718750.7343750.75

0.7656250.781250.7968750.8125

0.8281250.843750.8593750.875

0.8906250.906250.9218750.9375

0.9531250.968750.9843751.00

33/6417/3235/649/16

37/6419.3239/645/8

41/6421/3243/6411/16

45/6423/3247/643/4

49/6425/3251/6413/16

53/6427/3255/647/8

57/6429/3259/6415/16

61/6431/3263/641

0.39690.79371.19061.5875

1.98442.38122.77813.1750

3.57193.96874.36564.7625

5.15945.55625.95316.3500

6.74697.14377.54067.9375

8.33448.73129.12819.5250

9.921910.318710.715611.1125

11.509411.906212.303112.7000

0.0156250.031250.0468750.0625

0.0781250.093750.1093750.125

0.1406250.156250.1718750.1875

0.2031250.218750.2343750.25

0.2656250.281250.2968750.3125

0.3281250.343750.3593750.375

0.3906250.406250.4218750.4375

0.4531250.468750.4843750.50

INCHMILLI-

METERINCHMILL-

METERSINCHMILLI-

METERS

1234

5678

9101112

13141516

17181920

21222324

25262728

29303132

33

2.63782.67722.71652.7559

2.79532.83462.87402.9134

2.95272.99213.03153.0709

3.11023.14963.18903.2283

3.26773.30713.34643.3858

3.42523.46463.50393.5433

3.58273.62203.66143.7008

2.74013.77953.81893.85833.89763.9370

67686970

71727374

75767778

79808182

83848586

87888990

91929394

9596979899

100

1.33.861.37791.41731,4567

1.49611.53541.57481.6142

1.65351.69291.73231.7716

1.81101.85041.88981.9291

1.96852.00792.04722.0866

2.12602.16532.20472.2441

2.28352.32282.36222.4016

2.44092.48032.51972.5590

2.5984

34353637

38394041

42434445

46474849

50515253

54555657

58596061

62636465

66

0.03940.07870.11810.1575

0.19680.23620.27560.3150

0.35430.39370.43310.4724

0.51180.55120.59050.6299

0.66930.70870.74800.7874

0.82680.86610.90550.9449

0.98421.02361.06301.1024

1.14171.18111.22051.2598

1.2992

TABLE A4 CONVERSION TABLEMillimeters to Inches

1 millimeter = .03937 inch.1 inch = 25.4 millimeter.

80797877

76757473

7271

ABC

.1935

.1960

.1990

.2010

.2040

.2055

.2090

.2130

.2210

.2280

.386

.397

.404

.413

.0135

.0145

.0160

.0180

.0200

.0210

.0225

.0240

.0250

.0260

.234

.238

.242

.0280

.0292

.0310

.0320

.0330

.0350

.0360

.0370

.0380

.0390

.246

.250

.257

60595857

56555453

5251

GHI

.0400

.0410

.0420

.0430

.0465

.0520

.0550

.0595

.0635

.0670

.261

.266

.272

50494847

46454443

4241

JKL

.0700

.0730

.0760

.0785

.0810

.0820

.0860

.0890

.0935

.0960

.277

.281

.290

40393837

36353433

3231

MNO

.0980

.0995

.1015

.1040

.1065

.1100

.1110

.1130

.1160

.1200

.295

.302

.316

30292827

26252423

2221

PQR

.1610

.1660

.1695

.1730

.1770

.1800

.1820

.1850

.1890

.1910

.348

.358

.368

.377

20191817

16151413

1211

STUV

.1285

.1360

.1405

.1440

.1470

.1495

.1520

.1540

.1570

.1590

.323

.332

.339

10987

6543

21

WXYZ

TABLE A5NUMBER DRILL SIZES TO DECIMAL INCH

LETTER DRILL SIZES TO DECIMAL INCH

70696867

66656463

6261

DEF

FRAC-TIONAL

INCH

55

++

TABLE A6 HARDNESS VALUE CONVERSIONSHardened Carbon Steel and Hard Alloys

71706968

67666564

63626160

59585756

55545352

51504948

47464544

43424140

39383736

35343332

31302928

27262524

23222120

87.086.586.085.6

85.084.583.983.4

82.882.381.881.2

80.780.179.679.0

78.578.077.476.8

76.375.975.274.7

74.173.673.172.5

72.071.570.970.4

69.969.468.968.4

67.967.466.866.3

65.865.364.764.3

63.863.362.862.4

62.061.561.060.5

86.586.085.084.4

83.682.881.981.1

80.179.378.477.5

76.675.774.873.9

73.072.071.270.2

69.468.567.666.7

65.864.864.063.1

62.261.360.459.5

58.657.756.855.9

55.054.253.352.1

51.350.449.548.6

47.746.845.945.0

44.043.242.341.5

78.577.576.575.4

74.273.372.071.0

69.968.867.766.6

65.564.363.262.0

60.959.858.657.4

56.155.053.852.5

51.450.349.047.8

46.745.544.343.1

41.940.839.638.4

37.236.134.933.7

32.531.330.128.9

27.826.725.524.3

23.122.020.719.6

.-972946920

895870846822

799776754732

710690670650

630612594576

558542526510

495480466452

438426414402

391380370360

351342334326

318311304297

290284278272

266261256251

----

----

---

613

599587575561

546534519508

494481469455

443432421409

400390381371

362353344336

327319311301

294286279271

264258253247

243237231226

.----

----

----

326315305295

287278269262

253245239232

225219212206

201196191186

181176172168

163159154150

146142138134

131127124121

118115113110

-94.093.593.2

92.992.592.291.8

91.491.190.790.2

89.889.388.988.3

87.987.486.986.4

85.985.585.084.5

83.983.583.082.5

82.081.580.980.4

79.979.478.878.3

77.777.276.676.1

75.675.074.573.9

73.372.872.271.6

71.070.569.969.4

KNOOP500 GR.& OVER45-N30-N15-NAC

TENSILESTRENGTH*APPROX.

BRINELL3000KG

100989694

92918988

86848280

78767574

72706860

64626058

56545250

49474543

41393735

33312927

252321

(19)

(17)(15)(13)(11)

(8)(7)(2)(0)

.---

----

----

--

99.599.0

97.098.095.594.5

93.592.091.090.0

89.087.586.585.5

85.084.082.581.5

80.579.078.077.0

75.574.573.572.5

71.070.069.068.0

66.566.564.563.5

61.561.058.057.0

82.081.080.078.5

77.577.077.575.0

74.073.071.570.0

69.067.567.066.0

65.063.562.060.5

59.558.056.555.0

54.052.551.049.5

49.047.546.045.0

43.542.040.539.5

38.036.535.534.0

32.531.029.528.5

27.025.524.023.0

20.520.016.515.0

72.070.068.066.0

64.563.561.560.5

58.557.055.053.0

51.048.049.547.5

45.543.541.539.5

37.535.533.531.0

29.027.025.023.0

22.019.517.515.5

13.511.09.07.0

5.03.01.0-

----

----

----

61.560.559.057.5

56.556.055.054.0

53.052.050.549.5

48.547.046.546.0

45.044.043.042.0

41.540.539.538.5

-37.036.035.0

-34.033.032.0

31.030.529.528.5

-27.026.025.0

-23.022.521.5

21.020.0

--

----

251241231221

211206196192

184176170164

158º152150147

143139135131

127124120117

114111109107

106104102100

98969492

9088-

85

---

79

-76-

73

71-

6867

240228216205

195190180176

169162156150

144139137135

130125121117

114110107104

10187**85**83**

82**80**79**77**

75**74**72**71**

69**68**

--

64**-

62**61**

60**59**58**

-

-56**54**53**

93.0---

90.5-

89.5-

88.588.0

-86.5

86.0-

85.0-

84.083.5

-82.0

81.5--

79.5

79.0-

77.577.0

76.576.0

-74.5

74.0-

72.572.0

--

70.069.5

-68.067.567.0

-66.565.0

-

63.563.061.5

-

KNOOP500 GR.& OVER15-T30-T45-TFB

TENSILESTRENGTH*APPROX.

BRINELL3000KGA

11610910398

93918785

81787572

----

----

----

----

----

----

----

----

----

----

NOTE: The attached paragraph from ASTM F-606 gives both the "normal" and arbitration methods for hardness testing of fasteners.

3. TEST METHODS FOR EXTERNALLY THREADED FASTENERS3.1 PRODUCT HARDNESS. For routine inspection, hardness ofbolts and studs may be determined on the ends, wrench flats, orunthreaded shanks after removal of any oxide, decarburization,plating, or other coating material. Rockwell or Brinell hardness maybe used at the option of the manufacturer, taking into account thesize and grade of the product. For purpose of arbitration, hardness

shall be determined at mid-radius of a transverse section of the producttaken at a distance of one diameter from the point end of the product.The reported hardness shall be the average of four hardness readingslocated at 90° to one another. The preparation of test specimens andthe performance of hardness tests for Rockwell and Brinell testingsshall be in conformity with the requirements of Test Methods E 18 and E10, respectively.

* Tensile Strength is psi x 1000. Values in ( ) below normal value.** Below Brinell 101 tests were made with 500 kg. load.

1 Conversions are never numerically exact.2 The approximate tensile strength cross-reference holds for carbon steel only.3 Further detail may be found by reference to ASTM E-140.

++

ROCKWELL ROCKWELL

Soft Carbon Steel

56

Steel, by definition, is a combination of iron and carbon. Variousother elements are added to steel to improve physical propertiesand to produce special properties, such as resistance to corro-sion or heat. The specific effects of the addition of such elementsare outlined below:

ALUMINUM (AI). Aluminum is a deoxidizer and degasifier. Itretards grain growth and is used to control austenitic grain size.In nitriding steels, aluminum aids in producing a uniformly hardand strong nitrided case when used in amounts of 1.00% - 1.25%.

BORON (B). A potent and economical addition to a fully deoxi-dized steel; normally used in alloy steels. Added to the melt inextraordinarily small amounts (on the order of 0.001%), it has apowerful effect on hardenability. During times of shortages ofnickel, chromium and molybdenum, boron is used to replace aportion of these elements which are used to increase hardenability.Boron cannot be added in large amounts as it caused hot-short-ness (brittleness in steel in the hot forming range).

BISMUTH (Bi). Used in the same manner as lead as an additivein small amounts to improve machinability in the faster machin-ing grades of certain proprietary screw machine steels.

Carbon (C). While carbon is not usually considered an alloyingelement, it is the most important constituent of steel. It increasesthe tensile strength, hardness and resistance to wear and abra-sion. However, carbon lowers the ductility, machinability andtoughness.

CHROMIUM (Cr). Chromium increases tensile strength, tough-ness, hardness and hardenability, as well as resistance to wearand abrasion. It also increases resistance to corrosion and scal-ing at elevated temperatures.

COBALT (Co). Cobalt increases strength and hardness in addi-tion to permitting higher quenching temperatures. Also, it intensi-fies the effects of the other major elements in more complex steels.

COLUMBIUM (Cb). Columbium in stainless steel has an effectsimilar to titanium and tantalum in making the steel more resis-tant to carbide precipitation and the resulting inter-granular cor-rosion.

COPPER (Cu). Copper improves resistance to atmospheric cor-rosion and increases the tensile and yield strength with very littleloss in ductility.

IRON (Fe). Iron is the chief element from which the various steelsare made. Pure iron lacks strength, is very soft and ductile anddoes not respond satisfactorily to heat treatment. Commercialiron normally contains other elements which produce the requiredphysical properties.

LEAD (Pb). Lead, while not strictly an alloying element, is addedto improve machinability. It is almost completely insoluble in steel,and minute lead particles, dispersed throughout the steel, reducefriction where the cutting edge contacts the work. Also, the addi-tion of lead improves chip-breaking formations.

EFFECTS OF ALLOYING ELEMENTS IN STEEL

MANGANESE (Mn). Manganese is a deoxidizer and degasifier.It also reacts with sulphur to improve forgeability. Manganeseincrease tensile strength, hardness, hardenability, resistance towear and the rate of carbon penetration in carburizing. It alsodecreases the tendency toward scaling and distortion.

MOLYBDENUM (Mo). Molybdenum increase strength, tough-ness, hardness, and hardenability as well as creep resistanceand strength at elevated temperatures. It improves machinabil-ity, corrosion resistance and intensifies the effects of the otheralloying elements. In hot-work steels, molybdenum increasesred-hardness properties.

NICKEL (Ni). Nickel increases strength and hardness with noloss of ductility and toughness. It also increases resistance tocorrosion and scaling at elevated temperatures when introducedsuitable quantities in high chromium stainless steels.

NITROGEN (N). Important in several respects; 1) as a strongaustenitizer which can substitute for a portion of the nickel in stain-less steels; 2) as an element in nitriding and carbonitriding cer-tain alloy steels containing aluminum or chromium to produce anextremely hard case; 3) added to the melt of some of the free-machining steels to enhance machinability by producing a varyfine chip.

PHOSPHORUS (P). Phosphorus increases strength and hard-ness and improves machinability. However, it adds brittleness orcold-shortness to steel.

SELENIUM (Se). Related to sulphur and tellurium in the chemi-cal classification of elements, it has the similar effect of improv-ing machinability when added in small amounts to some free-machining steels.

SILICON (Si). Silicon is a deoxidizer and degasifier. Also, it in-creases the tensile and yield strength, forgeability, hardness andmagnetic permeability.

SULPHUR (S). Sulphur improves machinability in free-cuttingsteels. It decreases weldability, ductility and impact strength. Also,the addition of sulphur without sufficient manganese producesbrittleness at red heat.

TANTALUM (Ta). Tantalum is used as a stabilizing element instainless steels. It has a high affinity for carbon and forms car-bides which are uniformly dispersed throughout the steel, thuspreventing localized depletion of carbon at grain boundaries.

TITANIUM (Ti). Titanium, like tantalum and columbium, is addedto stainless steels to make them resistant to harmful carbide pre-cipitation.

TUNGSTEN (W). Tungsten increases strength, toughness andhardness. At elevated temperatures tungsten steels have supe-rior hotworking characteristics and greater cutting efficiency.

VANADIUM (V). Vanadium increases strength, hardness, andimpact resistance. By retarding grain growth vanadium permitshigher quenching temperatures. It also improves the red-har-ness properties of high-speed mental cutting tools and intensi-fies the individual effects of other major elements.

57

METRICFASTENERS

58

TABLE OF CONTENTS

DIMENSIONAL DATA Page No.

Metric Warning ..................................................................................................................................................... 60

Socket Head Cap Screws-Metric Series ......................................................................................................... 61-64

Metric Socket Button Head Cap Screws .............................................................................................................. 65

Metric Socket Flat Countersunk Head Cap Screws ........................................................................................ 66,67

Metric Socket Head Shoulder Screws............................................................................................................. 68,69

Metric Socket Set Screws ............................................................................................................................... 70-72

Metric Hexagon and Spline Sockets .................................................................................................................... 73

Metric Allen Wrenches and Bits ........................................................................................................................... 74

Metric Allen Spline Keys and Bits ........................................................................................................................ 75

Metric Dowel Pins ................................................................................................................................................ 76

Metric Holo-Krome Thread Standards ............................................................................................................ 77-79

MECHANICAL PROPERTIES AND APPLICATIONS DATA ............................................................................... 80

Mechanical Properties and Applications Data...................................................................................................... 81

Mechanical Properties-Socket Head Cap Screws-Metric Series ......................................................................... 82

Torque Data-Socket Head Cap Screws-Metric Series ......................................................................................... 83

Decarburization and Discontinuity Limits ............................................................................................................. 84

Holo-Krome Stainless Steel Metric Socket Head Cap Screws ............................................................................ 85

Holo-Krome Metric Socket Button Head, Metric Socket Flat Countersunk Head Screws.................................... 86

Tightening Torque-Metric Socket Button Head, Metric Socket Flat Countersunk Head Screws ......................... 86

Mechanical Properties-Metric Socket Shoulder Screws ...................................................................................... 87

Metric Socket Set Screws-Axial Holding Power ................................................................................................... 88

Mechanical Properties-Metric Allen Wrenches and Bits ...................................................................................... 89

Mechanical Properties-Metric Dowel Pins ............................................................................................................ 90

Metric Fastener Related Standards ..................................................................................................................... 91

59

Metric Section

Index to Tables Page No.

Table 36 Holo-Krome Metric Socket Head Cap Screws-Dimensions .............................................................. 61

Table 37 Holo-Krome Metric Socket Head Cap Screws-Grip and Body Lengths ............................................ 62

Table 38 Functional Limits for Runout of Head, Body, and Thread on Metric Socket Head Cap Screws ....... 63

Table 39 Drill and Counterbore Sizes-Metric Series........................................................................................ 64

Table 40 Metric Hexagon Socket Button Head Cap Screws-Dimensions ....................................................... 65

Table 41 Metric Hexagon Socket Flat Countersunk Head Cap Screws-Dimensions ...................................... 66

Table 42 Metric Hexagon Socket Flat Countersunk Head Cap Screws-Body and Grip Lengths .................... 67

Table 43 Metric Hexagon Socket Head Shoulder Screws-Dimensions ........................................................... 68

Table 44 Metric Hexagon and Spline Socket Set Screws-Dimensions ........................................................... 70

Table 45 Dimensions of Points of Metric Socket Set Screws .......................................................................... 71

Table 46 Dimensions of Metric Spline Sockets ............................................................................................... 73

Table 47 Dimensions of Metric Hexagon Sockets ........................................................................................... 73

Table 48 Dimensions of Metric Allen Wrenches and Bits ................................................................................ 74

Table 49 Dimensions of Metric Allen Spline Keys and Bits ............................................................................. 75

Table 50 Dimensions of Metric Dowel Pins ..................................................................................................... 76

Table 51 Metric Screw Thread Standards ....................................................................................................... 77

Table 52 External Thread-Limiting Dimensions M Profile ................................................................................ 78

Table 52A Limit Values for M Profile Minium Rounded Root Radius ................................................................. 78

Table 53 Diameter/Thread Pitch Comparison ................................................................................................. 79

Table 54 Metric Socket Head Cap Screws, Mechanical Properties ................................................................ 82

Table 55 Metric Socket Head Cap Screws, Tightening Torque Data .............................................................. 83

Table 56 Metric Socket Head Cap Screws, Decarburization Limits ................................................................ 84

Table 57 Metric Socket Head Cap Screws, Stainless Steel, Mechanical Properties....................................... 85

Table 58 Metric Button Head, Flat Countersunk Head Socket Cap Screws, Mechanical Properties .............. 86

Table 59 Metric Button Head, Flat Countersunk Head Socket Cap Screws, Tightening Torque .................... 86

Table 60 Holo-Krome Metric Shoulder Screws................................................................................................ 87

Table 61 Holo-Krome Metric Set Screws-Axial Holding Power ....................................................................... 88

Table 62 Holo-Krome Metric Allen Wrenches and Bits-Mechanical and Application Data .............................. 89

Table 63 Holo-Krome Metric Dowel Pins-Mechanical Properties .................................................................... 90

Table 64 Metric Fastener Related Standards .................................................................................................. 91

60

It is very important that the users of Socket Products,particularly Socket Head Cap Screws, be aware that thepractice in Europe and other metric areas, is not torestrict the manufacturer of these products to Class12.9. In the USA, and in inch module parts, it has beencustomary that the socket head cap screw configura-tion is always made from alloy steel and always to a

high strength level, typically 180,000 psi. Metric coun-tries produce this same configuration in alloy steels inClass 10.9 as well, and in Class 8.8 from carbon steel.It is vitally important that an assembly designed aroundClass 12.9 cap screws be put together with such screws.Beware of lower strength screws being substituted.

Warning Metric Users!

TYPE SIZE RANGE

DIAMETER LENGTH

M3to

M24

M3to

M20

M3to

M22

M3to

M16

6mmto

16mm

SHORT ARM

0.7 to 19mm

Socket HeadCap Screw

FlatCountersunk HeadSocketScrews

Button HeadSocket Screws

Cup PointSocketSet Screws

Hexagon SocketHead ShoulderScrews

Metric Allen Wrenches

5 to 35mmthru

40 to 150mm

8 to 30 mmthru

35 to 100mm

8 to 16mmthru

10 to 40mm

3 to 16mmthru

20 to 50mm

10 to 90mm

LONG ARM

0.7 to 19mm

Holo-Krome Metric Socket Screw Products

61

TABLE 36 HOLO-KROME METRIC SOCKET HEAD CAP SCREWS

TABLE 36 DIMENSIONS

NOMINALSIZEAND

THREADPITCH

BODYDIAMETER

D A H S J M T G B E F K LT

MAX. MIN.

HEADDIAMETER

MAX. MIN.

HEADHEIGHT

MAX. MIN.

CHAMFEROR RADIUS

MAX.

HEXAGONSOCKET

SIZE

NOM.

SPLINESOCKET

SIZE

NOM.

KEYENGAGE-

MENT

MIN.

WALLTHICK-NESS

MIN.

TRANSITIONDIAMETER

TRANSITIONLENGTH

JUNCTURERADIUS

MAX. MIN.

THREADLENGTH

CHAMFEROR

RADIUS

MAX. MIN. MAX. MIN.

M1.6 x0.35M2 x 0.4M2.5 x 0.45M3 x 0.5

M4 x 0.7M5 x 0.8M6 x 1M8 x 1.25

M10 x 1.5M12 x 1.75M14 x 2 (1)M16 x 2

M20 x 2.5M24 x 3M30 x 3.5M36 x 4

M42 x 4.5M48 x 5

1.602.002.503.00

4.005.006.008.00

10.0012.0014.0016.00

20.0024.0030.0036.00

42.0048.00

0.160.200.250.30

0.400.500.600.80

1.001.201.401.60

2.002.403.003.60

4.204.80

1.521.912.402.89

3.884.865.857.83

9.8111.7913.7715.76

19.7323.7029.6735.64

41.6147.58

1.602.002.503.00

4.005.006.008.00

10.0012.0014.0016.00

20.0024.0030.0036.00

42.0048.00

2.873.654.335.32

6.808.279.74

12.70

15.6717.6320.6023.58

29.5335.4844.4253.37

62.3171.27

3.003.804.505.50

7.008.50

10.0013.00

16.0018.0021.0024.00

30.0036.0045.0054.00

63.0072.00

1.461.862.362.86

3.824.825.827.78

9.7811.7313.7315.73

19.6723.6729.6735.61

41.6147.61

0.801.001.251.50

2.002.503.004.00

5.006.007.008.00

10.0012.0015.0018.00

21.0024.00

1.8291.8292.4382.819

3.3784.6485.4867.391

----

----

--

1.51.52.02.5

3.04.05.06.0

8.010.012.014.0

17.019.022.027.0

32.036.0

15.216.017.018.0

20.022.024.028.0

32.036.040.044.0

52.060.072.084.0

96.0108.0

0.100.100.100.10

0.200.200.250.40

0.400.600.600.60

0.800.801.001.00

1.201.60

0.340.510.510.51

0.600.600.681.02

1.021.871.871.87

2.042.042.892.89

3.063.91

1.82.22.73.2

4.45.46.58.8

10.813.215.217.2

21.625.632.038.0

44.451.2

2.02.63.13.6

4.75.76.89.2

11.214.216.218.2

22.426.433.439.4

45.652.6

0.080.080.080.13

0.130.130.200.20

0.200.250.250.25

0.400.400.400.40

0.400.40

0.540.680.851.02

1.521.902.283.20

4.004.805.606.40

8.009.60

12.0014.40

16.8019.20

UNDERHEAD FILLET

(1) The M14x2 size is not recommended for use in new designs.

NOTES FOR TABLE 36

1. LENGTH L. The length of the screw is the distance measured on aline parallel to the axis, from the plane of the bearing surface under thehead to the plane of the flat of the point. It includes the threads and thebody.

2. THREAD LENGTH LT. Thread length of the screw is the distance fromthe extreme point to the last complete or full form thread. It is controlledby the grip length, LG, as defined below. See Table 37 for grip and bodylengths of standard screws. LT min. refers to screws outside the range ofTable 37.

3. BODY LB. The unthreaded cylindrical portion of the shank for screwsthat are not threaded to the head.

4. GRIP LENGTH LG. The maximum length representing the designlength of the screw. It is measured from the bearing surface of the head,parallel to the axis of the screw, to the face of a GO thread ring gage withthe countersink and/or counterbore removed. See page 62 for grip andbody lengths of standard screws.

5. HEAD DIAMETER A. Heads may be made plain or knurled at Holo-Krome's option, unless specified on the order. For knurled screws, themaximum head diameter includes the knurl. Minimum head diameter isthe diameter of the head before knurling, or any unknurled section orband on the head. Sizes M5 and larger shall be marked with H-K logoand strength level.

6. HEAD CONCENTRICITY. The heads of Holo-Krome Metric SocketHead Cap Screws are concentric with the shank within 2% of the basicscrew diameter, or 0.15mm, whichever is greater, FIM (Full IndicatorMovement).

7. SOCKET TRUE POSITION. The axis of the socket shall be located attrue position relative to the axis of the screw within a tolerance zone hav-ing a diameter equal to 3% of the basic screw diameter or 0.26mm, which-ever is greater, for nominal screw sizes up to and including 12mm, andequal to 6% of the basic screw diameter for sizes larger than 12mm—regardless of feature size.

8. BEARING SURFACE. The plane of the bearing surface is perpen-dicular to the axis of the screw within a maximum deviation of 1 degree.

9. THREADS. Threads are Metric coarse series in accordance with ANSI/ASME B 1.13M - Metric Screw Threads, M Profile.

10. THREAD TOLERANCE CLASS. Threads are Tolerance Class 4g6gand for plated screws the allowance g may be consumed by the thick-ness of plating, so that the maximum limit of six after plating shall be thatof Tolerance Class 4h6h.

11. THREAD GAGING. Acceptability of screw threads shall be deter-mined based on System 22 of ANSI/ASME B1.3M.

12. POINT CHAMFER. The point shall be flat or slightly concave andchamfered. The chamfer shall extend slightly below the root of the thread,and the edge between the flat and chamber may be slightly rounded.The included angle of the point shall be approximately 90°. Chamferingon screw sizes up to and including mm and of larger screws with lengthsshorter that 0.75 times the basic screw diameter shall be optional.

13. FILLET. For all lengths of screws, the form of the fillet at the junctionof head and shank shall be optional within the following provisions: Thefillet shall be a smooth and continuous concave curve fairing into thebearing surface within the limits of diameter BV, with a junction radius ofnot less than F, and blending into the shank at a distance from the headnot exceeding E, as determined at the basic screw diameter D.

14. TOTAL RUNOUT. The total runout between the head body and threadon socket cap screws shall be such that the screw will assembly into acompound hole (see Table 38), that is threaded at one end to the basicthread size (class 6H min.) for a depth equivalent to 1.5 times the basicscrew diameter and counterbored at the other end of diameter AE andthrough the center portion to diameter DE as specified in Table 38. Thesediameters shall b e concentric with the axis of the thread within the equiva-lent of 10% of the thread pitch diameter tolerance. The starting threadshall be chamfered and the juncture of the corners shall be chamfered orrounded to a diameter equal to B maximum.

Applicable Standards and SpecificationsASME/ANSI B18.3.1M and ASTM A574M


GRIP LENGTH — LG. The maximum distance from the bearing surface of the head to the firstcompleted for full form thread. A clamped part thinner than LG would not allow the screw to seat.

BODY LENGTH — LB. The minimum length of the unthreaded cylindrical portion of the shank.

NOMINALSIZE


M1.6 M2 M2.5 M3 M4 M5 M6 M8 M10 M12 M14 M16 M20 M24

NOMINALLENGTH

LG LB LG LB LG LB LG LB LG LB LG LB LG LB

LG LB LG LB LG LB LG LB LG LB LG LB LG LB

20253035

40455055

60657080

90100110120

130140150160

180200220240

260300

4.89.8

14.8—

————

————

————

————

————

—

3.08.0

13.0—

————

————

————

————

————

——

4.09.0

14.019.0

24.0———

————

————

————

————

——

2.07.0

12.017.0

22.0———

————

————

————

————

——

8.013.018.0

23.028.033.0—

————

————

————

————

——

5.710.715.7

20.725.730.7—

————

————

————

————

——

7.012.017.0

22.027.032.037.0

42.047.0——

————

————

————

——

4.59.5

14.5

19.524.529.534.5

39.544.5——

————

————

————

——

10.015.0

20.025.030.035.0

40.045.050.060.0

————

————

————

——

6.511.5

16.521.526.531.5

36.541.546.556.5

————

————

————

——

13.0

18.023.028.033.0

38.043.048.058.0

68.078.0——

————

————

——

9.0

14.019.024.029.0

34.039.044.054.0

64.074.0——

————

————

——

11.0

16.021.026.031.0

36.041.046.056.0

66.076.086.096.0

————

————

——

6.0

11.016.021.026.0

31.036.041.051.0

61.071.081.091.0

————

————

——

17.022.027.0

32.037.042.052.0

62.072.082.092.0

102.0112.0122.0132.0

————

——

10.715.720.7

25.730.735.745.7

55.765.775.785.7

95.7105.7115.7125.7

————

——

18.023.0

28.033.038.048.0

58.068.078.088.0

98.0108.0118.0128.0

148.0168.0

——

——

10.515.5

20.525.530.540.5

50.560.570.580.5

90.5100.5110.5120.5

140.5160.5

——

——

24.029.034.044.0

54.064.074.084.0

94.0104.0114.0124.0

144.0164.0184.0204.0

——

15.220.225.235.2

45.255.265.275.2

85.295.2

105.2115.2

135.2155.2175.2195.2

——

25.030.040.0

50.060.070.080.0

90.0100.0110.0120.0

140.0160.0180.0200.0

220.0—

15.020.030.0

40.050.060.070.0

80.090.0

100.0110.0

130.0150.0170.0190.0

210.0—

26.036.0

46.056.066.076.0

86.096.0106.0116.0

126.0146.0166.0186.0

206.0246.0

16.026.0

36.046.056.066.0

76.086.096.0

106.0

136.0156.0176.0196.0

216.0256.0

38.048.058.068.0

78.088.098.0108.0

128.0148.0168.0188.0

208.0248.0

25.535.545.555.5

65.575.585.595.5

115.5135.5155.5175.5

195.5235.5

40.050.060.0

70.080.090.0

100.0

120.0140.0160.0180.0

200.0240.0

25.035.045.0

55.065.075.085.0

105.0125.0145.0165.0

185.0225.0

NOTES FOR TABLE 37

1. Screws of diameter/length combinations above heavy line shall be threaded full length.

2. For screw sizes and/or lengths not tabulated, see Note 2, Table 36.


NOMINAL SIZE

TABLE 38 FUNCTIONAL LIMITS FOR RUNOUT OF HEAD, BODY, AND THREAD ON METRIC SOCKET HEAD CAP SCEWS

M1.6 M2 M2.5 M3 M4 M5 M6 M8 M10 M12

NOMINAL LENGTH HOLE DIAMETERS FOR SHANK DE AND FOR HEAD AE

OVER TO. INCL. DE AE DE AE DE AE DE AE DE AE DE AE

DE AE DE

AE DE AE DE AE

06

122025

012253550

020356070

0255070

100

612202535

1225355060

20356070

100

255070

100150

1.661.721.801.85—

—————

—————

—————

3.213.273.353.40—

—————

—————

—————

2.052.112.182.222.31

—————

—————

—————

4.004.064.134.174.26

—————

—————

—————

—————

2.602.702.782.90—

—————

—————

—————

4.754.854.935.05—

—————

—————

—————

3.093.183.253.363.44

—————

—————

—————

5.745.835.906.016.09

—————

—————

—————

—————

4.134.224.384.444.63

—————

—————

—————

7.287.377.537.597.78

—————

—————

—————

5.125.205.345.395.56

—————

—————

—————

8.778.858.999.049.21

—————

—————

—————

—————

6.136.266.366.516.64

—————

—————

—————

10.1810.4110.5110.6610.79

—————

—————

—————

8.118.228.318.448.64

—————

—————

—————

13.2713.3813.4713.6013.80

—————

—————

—————

10.1010.2010.2810.4010.60

—————

—————

—————

16.3016.4016.4816.6016.80

—————

—————

—————

12.0912.1812.2512.3612.54

—————

—————

—————

18.3318.4218.4918.6018.78

NOMINAL SIZE M14 M16 M20 M24 M30 M36 M42 M48

NOMINAL LENGTH HOLE DIAMETERS FOR SHANK DE AND FOR HEAD AE

OVER TO. INCL. DE AE DE AE DE AE DE AE DE AE DE AE

DE AE DE

AE

050

100150200

0150300450

50100150200250

150300450600

14.1714.3414.5014.6414.64

————

21.4521.6221.7821.9221.92

————

16.1616.3216.4716.6316.64

————

24.4824.6424.7924.9524.96

————

20.1420.2820.4220.5620.64

————

30.5430.6830.8230.9631.04

————

24.1324.2624.3824.5124.64

————

36.6136.7436.8636.9937.12

————

—————

30.3830.7531.1231.50

—————

45.9846.3546.7247.10

—————

36.3836.7537.1237.50

—————

55.1055.4755.8456.22

—————

42.3842.7543.1243.50

—————

64.2264.5964.9665.34

—————

48.3848.7549.1249.50

—————

73.3473.7174.0874.46

64


TABLE 39 DRILL AND COUNTERBORE SIZES - METRIC SERIES

M1.6M2M2.5M3

M4M5M6M8

M10M12M14M16

M20M24M30M36

A X C

NOMINAL DRILL SIZE

CLOSE FIT NORMAL FIT COUNTERBORE COUNTERSINK DIAMETER NOMINAL SIZE [NOTE (2)] [NOTE (3)] DIAMETER [NOTE (1)]

2.02.63.13.6

4.75.76.89.2

11.214.216.218.2

22.426.433.439.4

3.504.405.406.50

8.259.75

11.2514.25

17.2519.2522.2525.50

31.5037.5047.5056.50

1.952.403.003.70

4.805.806.808.80

10.8012.8014.7516.75

20.7524.7531.7537.50

NOTES FOR TABLE 36

1. COUNTERSINK. It is considered good practice to countersink orbreak the edges of holes that are smaller than B maximum in partshaving a hardness that approaches, equals, or exceeds the screwhardness. If such holes are not countersunk, the heads of screwsmay not seat properly or the sharp edges on the hole may deform thefillets on screws, thereby making them susceptible to fatigue inapplications involving dynamic loading. The countersink or cornerrelief, however, should not be larger than is necessary to insure thatthe fillet on the screw is cleared. Normally, the diameter of countersinkdoes not have to exceed B maximum.

Countersinks or corner reliefs in excess of this diameter reduce theeffective bearing area and introduce the possibility of imbedment wherethe parts to be fastened are softer than the screws, or of brinnelling orflaring the heads of the screws where the parts to be fastened areharder than the screws.

1.802.202.703.40

4.405.406.408.40

10.5012.5014.5016.50

20.5024.5030.7537.00

2. CLOSE FIT. The close fit is normally limited to holes for those lengthsof screws that are threaded to the head (see Table 38) in assemblies whereonly one screw is to be used or where two or more screws are to be usedand the mating holes are to be produced either at assembly or by matchedand coordinated tooling.

3. NORMAL FIT. The normal fit is intended for screws of relatively longlength or for assemblies involving two or more screws of relatively longlength or for assemblies involving two or more screws where the matingholes are to be produced by conventional tolerancing methods. It pro-vides for the maximum allowable eccentricity of the longest standard screwsand for certain variations in the parts to be fastened, such as: deviations inhole straightness, angularity between the axis of the tapped hole and thatof the hole for shank, differences in center distances of the mating holes,etc.

65

TABLE 40 HOLO-KROME METRIC HEXAGON SOCKET BUTTON HEAD CAP SCREWS

TABLE 40 DIMENSIONS

M3 x 0.5M4 x 0.7M5 x 0.8M6 x 1

M8 x 1.25M10 x 1.5M12 x 1.75M16 x 2

D A H S J T G B E R L

NOTES FOR TABLE 40

1. THREAD LENGTH. Screws of nominal lengths equal to or shorter thanthe length listed in column L shall be threaded full length. The distancemeasured parallel to the axis of the screw from the underside of the head tothe face of a non-countersunk standard GO ring gage assembled by handas far as the thread will permit, shall not exceed two pitches.

2. LENGTH. The length of the screw (L) shall be measured parallel to theaxis of the screw from the plane of the baring surface under the head to theplane of the flat of the point.

3. POINT. The points of button head cap screws shall be chamfered, withthe chamfer extending slightly below the root of the thread and the edgebetween the flat and the chamfer may be slightly rounded. The includedangle of the point shall be approximately 90°. Chamfering on screw sizesup to the including 4mm in diameter an of larger sizes with the length shorterthan 0.75 times the basic screw diameter, shall be optional..

NOMINAL SIZEAND

THREAD PITCH

HEADDIAMETER

HEADHEIGHT

HEADSIDE

HEIGHT

HEXAGONSOCKET

SIZE KEY

ENGAGEMENT TRANSITIONDIAMETER

TRANSITIONLENGTH

JUNCTURERADIUS

MAXIMUMSTANDARD

LENGTH

REF.MAX. MIN. MAX. MIN. NOM. MIN. MAX. MIN. MAX. MIN. NOM.

WALLTHICKNESS

MIN.

5.707.609.50

10.50

14.0017.5021.0028.00

5.407.249.14

10.07

13.5717.0720.4827.48

1.652.202.753.30

4.405.506.608.80

1.431.952.503.00

4.055.206.248.44

0.380.380.500.80

0.800.800.801.50

22.5

34

568

10

3.24.45.46.5

8.810.813.217.2

3.64.75.76.8

9.211.214.218.2

0.200.300.380.74

1.051.451.632.25

1.041.301.562.08

2.603.124.165.20

12203030

40406060

0.100.200.200.25

0.400.400.600.60

0.510.600.600.68

1.021.021.871.87

4. SOCKET TRUE POSITION. The axis of the socket shall be located attrue position relative to the axis of the screw within a tolerance zone havinga diameter equal to 3% of the basic screw diameter or 0.26mm, whichever isgreater, for nominal screw sizes up to 12mm, and qual to 6% of the basicscrew diameter for sizes larger than 12mm, regardless of feature size.

5. THREADS AND GAGING. Threads shall be metric coarse series, inaccordance with ANSI/ASME B1.13M, Metric Screw Threads, -M Profile.Acceptability of screw threads shall be determined based on System 22 ofANSI/ASME B1.3M.

6. THREAD TOLERANCE CLASS. Threads shall be Tolerance Class 4g6g.For plated screws the allowance g may be consumed by the plating so thatthe maximum limit of size after plating shall be 4h6h.

Applicable Standards and SpecificationsASME/ANSI B18.3.4M and ASTM F835M

66

TABLE 41 HOLO-KROME METRIC FLAT COUNTERSUNK SOCKET HEAD CAP SCREWS

TABLE 41 DIMENSIONS

M3 x 0.5M4 x 0.7M5 x 0.8M6 x 1

M8 x 1.25M10 x 1.5M12 x 1.75M14* x 2

M16 x 2M20 x 2.5

D A H J T G F

NOTES FOR TABLE 41

1. LENGTH L. The length of hexagon socket flat countersunk screws ismeasured on a line parallel to the axis, from the plane of top of the head tothe plane of the flat of the point.

2. THREAD LENGTH. The length of the screw is the distance from theextreme point to the last complete or full form thread. It is controlled by thegrip length, LGH as defined below. See Table 42 for grip and body lengths ofstandard screws.

3. BODY LBH. The unthreaded cylindrical portion of the shank for screwsthat are not threaded to the head. This represents the minimum length offull body plus the reference head height.

4. GRIP LENGTH LGH. The maximum length representing the design griplength of the screw. It is measured from the top of the head, parallel to theaxis of the screw, to the face of a GO thread ring gage with the countersinkand/or counterbore removed. See Table 42 for grip and body lengths.

5. POINT> The points of flat countersunk cap screws shall be chamfered,with the chamfer extending slightly below the root of the thread and theedge between the flat and the chamfer may be slightly rounded. The in-cluded angle of the point shall be approximately 90°. Chamfering on screwsizes up to and including 4mm in diameter and of larger sizes with the lengthshorter than 0.75 times the basic screw diameter, shall be optional.

6. SOCKET TRUE POSITION. The axis of the socket shall be located attrue position relative to the axis of the screw within a tolerance zone havinga diameter equal to 3% of the basic screw diameter or 0.26mm, whicheveris greater, for nominal screw sizes up to 12mm, and equal to 6% of the basicscrew diameter for sizes larger than 12mm, regardless of feature size.

NOMINAL SIZEAND

THREAD PITCH

BODYDIAMETER

MAX. MIN.REFER-ENCE

FLUSHNESSTOLER-ANCE MIN. MIN. MAX.NOM.

3.04.05.06.0

8.010.012.014.0

16.020.0

2.863.824.825.82

7.789.78

11.7313.73

15.7319.67

6.728.96

11.2013.44

17.9222.4026.8830.80

33.6042.00

5.357.809.75

11.70

15.6019.5023.4026.52

29.0136.05

1.862.483.103.72

4.966.207.448.40

8.8011.00

1.11.51.82.4

3.03.64.65.5

5.57.2

2.02.53.04.0

5.06.08.0

10.0

10.012.0

0.250.250.300.35

0.400.400.450.50

0.500.75

0.250.350.400.50

0.600.800.901.00

1.001.20

0.310.450.660.70

1.161.621.801.80

2.202.20

SOCKETWALL

HEAD DIAMETER

HEXAGONSOCKET

SIZEKEY

ENGAGEMENTTHEORETICAL

SHARPMAX.

ABSOLUTEMIN.

HEAD HEIGHTFILLET

EXTENSIONABOVE D

NOTE *Not recommended for new design.7. CONCENTRICITY. Concentricity of the thread with the body shall bewithin 0.13mm per mm of body length (unthreaded portion) full (total) indica-tor reading, taken directly under the head when the screw is held by the fullthreads closest to the head of the screw and shall not exceed 0.64mm.

8. THREADS AND GAGING. Threads shall be metric coarse series, inaccordance with ANSI/ASME B1.13M, Metric Screw Threads, -M Profile.Acceptability of screw threads to be determined based on System 22 ofANSI/ASME B1.3M.

9. THREAD TOLERANCE CLASS> Threads shall be Tolerance Class 4g6g.For plated screws the allowance g may be consumed by the plating so thatthe maximum limit of size after plating shall be 4h6h.

10. HEAD DIAMETERS. The maximum sharp values listed under A inTable 41 are theoretical values, as it is not practical to make the edges of thehead sharp. The maximum sharp value represents the exact diameter ofthe hole countersunk to exactly 90° in which a screw having maximum headsize will it flush.

11. HEAD HEIGHT (H). The tabulated values for head height are given forreference only and are calculated to the maximum formulation.

12 FLUSHNESS TOLERANCE. The flushness tolerance is the distance thetop surface of the screw having the minimum head size will be below theflush condition in the hole countersunk exactly 90° to the maximum sharpdimension listed under A in Table 41.

13 . BEARING SURFACE. The axis of the conical bearing surface shall beparallel to the axis of the body with 1/2°.

Applicable Standards and SpecificationsASME/ANSI B18.3.5M and ASTM F 835M

67


HEXAGON SOCKET FLAT COUNTERSUNK HEAD CAP SCREWS (METRIC SERIES)

35404550

55606570

8090

100110

120130140150

M3 M4 M5 M6 M8 M10 M12 M14 M16 M20

NOMINALLENGTH

NOMINALDIAMETER

LGH

LBH

LGH LBHLGH LBH LGH LBH LGH LBH LGH LBH LGH LBH LGH LBH LGH LBH

LGH LBH

17222732

37

14.519.524.529.5

34.5

15202530

35404550

60

11.516.521.526.5

31.536.541.546.5

56.5

182328

33384348

586878

141924

29343944

546474

2126

31364146

56667686

96

1621

26313641

51617181

91

22

27323742

52627282

92102112122

15.7

20.725730.735.7

45.755.765.775.7

85.795.7105.7115.7

283338

48586878

8898

108118

20.525.530.5

40.550.560.570.5

80.590.5100.5110.5

2934

44546474

8494

104114

20.225.2

35.245.255.265.2

75.285.295.2105.2

30

40506070

80.90100110

20

30405060

708090

100

36465666

768696

106

26364656

66768696

58

68788898

45.5

55.565.575.585.5

NOMINAL SCREWDIAMETER

MAXIMUM TOTALTHREAD LENGTH

MINIMUM THREADLENGTH

M3M4M5M6

M8M10M12M14

M16M20

20.523.526.029.0

34.339.544.850.0

54.064.5

18.020.022.024.0

28.032.036.040.0

44.052.0

D LT LTT

TABLE 42A THREAD LENGTHS FOR LENGTHS NOTTABULATED IN TABLE 42

68

TABLE 43 HOLO-KROME METRIC HEXAGON SOCKET HEAD SHOULDER SCREWS

TABLE 43 DIMENSIONS OF METRIC HEXAGON SOCKET HEAD SHOULDER SCREWS

6.0*6.58.0

10.0

12.0*13.016.020.0

24.0*25.0

D A H S J T M R

NOMINALSCREWS SIZE

OR BASICSHOULDERDIAMETER

SHOULDERDIAMETER

MAX. MIN.

5.9876.4877.9879.987

11.98412.98415.98419.980

23.98024.980

5.9516.4517.9519.951

11.94112.94115.94119.928

23.92924.928

HEADDIAMETER

HEADHEIGHT

CHAMFEROR RADIUS

HEXAGONSOCKET SET

KEYENGAGEMENT

HEAD FILLETEXTENSIONDIAMETER

SHOULDERNECK FILLET

RADIUS

10.0013.0016.00

18.0024.0030.00

36.00

9.7812.7315.73

17.7323.6729.67

35.61

4.505.507.00

9.0011.0014.00

16.00

0.60.81.0

1.21.62.0

2.4

2.43.34.2

4.96.68.8

10.0

7.07.59.2

11.2

14.215.218.222.4

26.427.4

0.20.40.4

0.60.60.8

0.8

MAX. MIN. MAX. MIN.

4.325.326.78

8.7810.7313.73

15.73

MAX. MAX.MAX.MAX.MAX.

345

68

10

12

6.0*6.58.0

10.0

12.0*13.016.020.0

24.0*25.0

K F DT

G I N E

NOMINALSCREWS SIZE

OR BASICSHOULDERDIAMETER

SHOULDERNECK

DIAMETER

MIN.

5.425.927.429.45

11.4212.4215.4219.42

23.4224.42

SHOULDERNECKWIDTH

NORMAL THREADSIZE OR BASIC

THREADDIAMETER

THREADPITCH

THREAD NECKDIAMETER

THREAD NECKWIDTH

THREAD NECKFILLET RADIUS

THREADLENGTH

2.52.52.5

2.52.52.5

3.0

568

101216

20

0.81

1.25

1.51.75

2

2.5

2.42.62.8

3.04.04.8

5.6

0.660.690.80

0.931.031.30

1.46

9.7511.2513.25

16.4018.4022.40

27.40

3.864.586.25

7.919.57

13.23

16.57

MAX. MAX.MAX.MIN.

3.684.406.03

7.699.35

12.96

16.30

TABLE 43 DIMENSIONS (Continued)

MAX. MIN.MAX.

0.500.530.64

0.770.871.14

1.30

*These dimensions for product made prior to final standardization by USA and ISO.

69

NOTES FOR TABLE 43 (SHOULDER SCREWS)

1. SHOULDER. The shoulder is the enlarged unthreaded shank portion ofthe screw, the diameter of which serves as the basis for derivation of thenominal screw size. This diameter shall be ground to the limits for D speci-fied in Table 43 and a surface roughness not exceeding 0.8 m Ra.

2. LENGTH. The basic length of the socket head shoulder screw shall bethe nominal length of the shoulder, expressed in millimeters, measured par-allel to the axis of the screw, from the plane of the bearing surface of thehead to the plane of the shoulder at the threaded end.

3. STANDARD LENGTH. The standard lengths for shoulder screws shallbe as follows: 10, 12, 16, 20, 25, 30, 40, 50, 60, 70, 80, 90, 1000, 110, and120mm.

4. THREAD NECK. The neck portion between the thread and shouldershall allow the face of the shoulder to seat against the face of a standardbasic GO ring gage assembled onto the threaded end.

5. THREADS AND GAGING. Threads shall be the metric coarse series, inaccordance with ANSI/ASME B1.13M, Metric Screw Threads, M Profile.Acceptability of screw threads shall be based on System 22 of ANSI/ASMEB1.3M.

η

6. THREAD TOLERANCE CLASS. Threads shall be Tolerance Class 4g6g.For plated screws, the allowance g may be consumed by the thickness ofthe plating so that the maximum size limit after plating shall be that of Toler-ance Class 4h6h.

7. THREAD LENGTH TOLERANCE. The tolerance on the length of threadedportion shall be minus 0.50mm for nominal screw sizes up to and including10mm and 0.75mm for larger sizes.

8. CONCENTRICITY. The shoulder and thread pitch diameter shall be con-centric with 0.10mm full indicator movement (FIM), determined at a distanceof 4.75mm from the face of the shoulder.

Concentricity, parallelism, bow and squareness of the face of the shouldwith the axis of the thread shall be within 0.125mm FIM per 25 .0mm of theshoulder length, with maximum of 0.7mm, when the shoulder face is firmlyseated against a threaded bushing and deviation is checked on the shoulderat a distance of 2F from the underside of the head. The thread in the bush-ing shall be basic size, and the bushing outside diameter and ends shall beconcentric and square with the axis of the thread, respectively.

Applicable Standards and SpecificationsASME/ANSI B18.3.3M

70

TABLE 44 HOLO-KROME METRIC SOCKET SET SCREWS

TABLE 44 DIMENSIONS OF METRIC SOCKET SET SCREWS

0.60.81.0

1.25

0.60.81.01.21.5

0.71.11.51.8

0.61.11.52.12.1

1.01.31.82.32.3

1.22.02.72.72.7

D J M L T D J M L T

NOMINAL SIZEAND

THREAD PITCHHEXAGON

SOCKET SIZE

NOMINALSCREW

LENGTHS

SPLINESOCKET

SIZE


HALF DOGPOINTS

CONE ANDOVAL

POINTS

CUP ANDFLAT

POINTSHEXT

H

SPLT

S

HEXT

H

SPLT

S

HEXT

H

SPLT

S

MIN. MIN.MIN.MIN.MIN.MIN.NOM.NOM.

NOMINAL SIZEAND

THREAD PITCH

HEXAGONSOCKET

SIZENOMINALSCREW

LENGTHS

SPLINESOCKET

SIZE


HALF DOGPOINTS

CONE ANDOVAL

POINTS

CUP ANDFLAT

POINTSHEXT

H

SPLT

S

HEXTH

SPLTS

HEXTH

SPLTS

MIN. MIN.MIN.MIN.MIN.MIN.NOM.NOM.

0.60.70.70.7

0.60.70.70.70.7

0.71.01.01.0

0.61.11.21.21.2

1.01.31.82.02.0

1.22.02.32.32.3

0.60.81.0

1.25

0.60.81.01.21.5

0.71.11.31.8

-0.71.01.52.1

-1.01.52.02.3

-1.21.72.02.7

0.60.70.70.7

0.60.70.70.70.7

0.71.01.01.0

-0.71.01.21.2

-1.01.52.02.0

-1.21.72.02.3

-0.60.7

1.25

--

0.81.21.5

-0.91.21.8

--

1.02.02.1

-1.01.52.02.3

--

2.02.52.7

-0.60.70.7

--

0.70.70.7

-0.91.01.0

--

1.01.21.2

-1.01.52.02.0

--

2.02.32.3

1.52

2.53

1.52

2.534

22.5

34

22.5

345

2.53456

34568

0.84

0.84

1.22

1.52

2.44

2.82

0.7

0.9

1.3

1.5

2

2.5

M1.6 x 0.35

M2 x 0.4

M2.5 x 0.45

M3 x 0.5

M4 x 0.7

M5 x 0.8

1.82.53.03.0

1.82.54.04.0

2.03.65.05.0

3.04.56.06.0

3.04.88.08.0

-6.09.0

10.0

5.08.0

12.012.0

1.82.53.03.0

1.82.54.04.0

2.03.65.05.0

3.04.56.06.0

3.04.88.08.0

-6.09.010.0

5.08.012.012.0

-1.82.73.0

-2.33.54.0

-3.04.05.0

-3.85.06.0

-3.06.08.0

-5.08.0

10.0

-7.0

10.012.0

-1.82.73.0

-2.33.54.0

-3.04.05.0

-3.85.06.0

-3.06.08.0

-5.08.0

10.0

-7.0

10.012.0

-1.52.03.0

-1.83.04.0

-2.54.05.0

-3.55.06.0

-3.06.08.0

-5.08.0

10.0

-6.0

10.012.0

-1.52.03.0

-1.83.04.0

-2.54.05.0

-3.55.06.0

-3.06.08.0

-5.08.0

10.0

-6.0

10.012.0

4568

568

10

68

1012

8101216

10121620

12162025

16’202530

3.68

4.65

5.49

6.38

9.45

11.53

15.11

3

4

5

6

8

10

12

M6 x 1

M8 x 1.25

M10 x 1.5

M12 x 1.75

M16 x 2

M20 x 2.5

M24 x 3

71

TABLE 45 DIMENSIONS OF METRIC SOCKET SET SCREW POINTS

D C C1 C2 R Y A P Q

CONE POINT CUP POINT CUP POINT FLAT OVAL ANGLE 90° FOR FLAT OR HALF DOG POINT DIAMETER DIAMETER FOR POINT POINT THESE LENGTHS TRUNCATION

HOLO-KNURL POINT DIAMETER RADIUS AND OVER/118° FOR ON CONE POINT DIAMETER LENGTH MAX. MIN. MAX. MIN. MAX. MIN. MAX. MIN. SHORTER LENGTHS MAX. MIN. MAX. MIN. MAX. MIN.

M1.6 0.80 0.55 0.80 0.64 0.80 0.55 1.60 1.20 3 0.16 0 0.80 0.55 0.53 0.40M2 1.00 0.75 1.00 0.82 1.00 0.75 1.90 1.50 3 0.20 0 1.00 0.75 0.64 0.50M2.5 1.25 1.05 1.25 1.05 1.50 1.25 2.28 1.88 4 0.25 0 1.50 1.25 0.78 0.63M3 1.50 1.28 1.50 1.28 2.00 1.75 2.65 2.25 4 0.30 0 2.00 1.75 0.92 0.75

M4 2.00 1.75 2.00 1.75 2.50 2.25 3.80 3.00 5 0.40 0 2.50 2.25 1.20 1.00M5 2.50 2.22 2.50 2.22 3.50 3.20 4.55 3.75 6 0.50 0 3.50 3.20 1.37 1.25M6 3.00 2.75 3.00 2.69 4.00 3.70 5.30 4.50 8 1.50 1.2 4.00 3.70 1.74 1.50M8 4.00 3.65 4.00 3.65 5.50 5.20 6.80 6.00 10 2.00 1.6 5.50 5.20 2.28 2.00

M10 5.00 4.60 5.00 4.60 7.00 6.64 8.30 7.50 12 2.50 2.0 7.00 6.64 2.82 2.50M12 6.00 5.57 6.00 5.57 8.50 8.14 9.80 9.00 16 3.00 2.4 8.50 8.14 3.35 3.00M16 8.00 7.50 8.00 7.50 12.00 11.57 12.80 12.00 20 4.00 3.2 12.00 11.57 4.40 4.00M20 10.00 9.44 10.00 9.44 15.00 14.57 15.80 15.00 25 5.00 4.0 15.00 14.57 5.45 5.00

M24 12.00 11.39 12.00 11.39 18.00 17.57 18.80 18.00 30 6.00 4.8 18.00 17.57 6.49 6.00

NOMINAL

SIZE

72

NOTES FOR TABLE 44 and 45

1. LENGTH. The length of the screw shall be measured overall, parallel to theaxis of the screws.

2. TOLERANCE ON LENGTH. The tolerance on the screw length shall be:

3. STANDARD LENGTHS. The standard nominal screw lengths are 1.5, 2, 2.5,3, 4, 5, 6, 8, 10, 12, 16, 20, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80, 90, and 100mm.The minimum practical screw length for the respective screw sizes and pointstyles is represented by the shortest lengths listed in Table 44 for which T valuesare shown.

4. THREADS AND GAGING. Threads shall be the metric coarse series, inaccordance with ANSI/ASME B1.3M.

As standard gages provide only for engagement lengths up to the equivalent of1.5 times the thread diameter, changes in pitch diameter of either or both externaland internal thread may be required to longer lengths of engagement.

5. THREAD TOLERANCE CLASS. Threads shall be Tolerance Class 4g6g. Forplated screws, the allowance g may be consumed by the thickness of the platingso that the maximum size limit after plating shall be that of Tolerance Class 4h6h.

Nominal Screw Length,mm

Up to 12, incl.Over 12 to 50, incl.

Over 50

Length Tolerance,mm

± 0.3± 0.5± 0.8

6. KEY ENGAGEMENT. For screws of nominal lengths exceeding those in Table44, the minimum key engagement T for the longest length shown shall apply. Thisrepresents the minimum key engagement necessary to develop the full functionalcapability of the keys conforming to ANSI B18.3.2M, Metric series Hexagon Keysand Bits.

7. SOCKET GAGING. Acceptability of hexagon sockets shall be determined by theuse of hexagon socket gages specified in ASME/ANSI B18.3.6M. The hexagonsockets shall allow the GO members of the gage to enter freely to the minimumengagement depth. The NOT GO members shall be permitted to enter only to adepth of 10% of the nominal size for sockets up to and including 1.5mm, and 7.5% ofthe nominal socket size for larger sizes. Acceptability of spline sockets shall bedetermined in similar fashion, using the spline gages specified in ASME/ANSIB18.3.6M.

8. SOCKET TRUE POSITION. The axis of the socket shall be located at trueposition relative to the axis of the screw within a tolerance zone having a diameter of0.25mm, regardless of feature size.

9. FACE CHAMFER. The face on screws having a nominal length longer than thescrew diameter shall be chamfered. The chamfer angle V shall be between 30° and45°. The chamfer shall extend below the root of the thread, and the edge betweenthe face and the chamfer may be slightly rounded. For screws having a nominallength equal to or shorter than the nominal diameter, chamfering shall be at theoption of the manufacturer.

10. POINT ANGLE. The point angles specified shall apply only to those portions ofthe angles that lie below the root of the thread. The point angle W for flat and cuppoints shall be 45° +5°, -0°, for screws of length equal to the nominal screw diameterand longer, and 30° minimum for shorter screws.

11. OTHER POINTS. For other point configurations, see ASME/ANSI B18.3.6M

Applicable Standards and Specifications

ASME/ANSI B18.3.6M and ASTM F 912M.

73

TABLE 46 and 47 METRIC HEXAGON AND SPLINE SOCKETS

TABLE 46 DIMENSIONS OF METRIC SPLINE SOCKETS

0.841.221.522.44

2.823.684.655.49

6.3898.4511.5315.11

M N P

NOMINALSPLINE

SOCKETSIZE

NUMBEROF

TEETH

4666

6666

6666

SOCKETMAJOR

DIAMETER

SOCKETMINOR

DIAMETER

WIDTHOF

TOOTH

0.8891.2701.5752.489

2.9213.7854.7755.613

6.5029.652

11.76015.342

0.8641.2451.5492.464

2.8703.7344.7245.563

6.4529.576

11.68415.265

0.6601.0411.2952.083

2.4893.2514.1404.826

5.6138.1038.804

12.929

0.3050.3790.3560.559

0.6350.8130.9911.270

1.5242.3372.8453.505

MAX. MIN. MAX. MIN.

0.6481.0161.2702.032

2.4383.2004.0894.775

5.5638.0269.728

12.852

MAX. MIN.

0.2920.2540.3300.533

0.5840.7620.9401.219

1.4732.2612.7693.404

NOMINALSOCKET

SIZE

0.70.91.31.5

22.5

34

568

10

12

DIMENSIONSACROSS FLATS

0.7240L9021.2951.545

2.0452.5603.0714.084

5.0846.0958.115

10.127

12.146

0.7110.8891.2701.520

2.0202.5203.0204.020

5.0206.0208.025

10.025

12.032

MAX. MIN.

DIMENSIONSACROSS

CORNERS

0.8031.0031.4271.730

2.3002.8703.4404.580

5.7206.8609.15011.500

13.800

J C

TABLE 47 DIMENSIONS OF METRICHEXAGON SOCKETS

NOTES FOR TABLE 46

1. The tabulated dimensions represent direct soft metric conversions of theequivalent inch size spline sockets shown in Table 11. Therefore, the spline keysand bits shown in Table 49 are applicable for wrenching the corresponding sizemetric spline sockets.

2. Where spline sockets are chamfered, the depth of chamfer shall not exceed10% of the nominal socket size for sizes up to and including 1.52 and 7.5% forlarger sizes. For chamfered sockets, it is permissible for the NOT GO socketgage to enter to the depth of chamfer.

NOTES FOR TABLES 46 AND 47

1. SOCKET DEPTH (T). Applicable socket depths are specified in thedimensional tables and notes for the respective screw types.

2. SOCKET CHAMFER. Where sockets are chamfered, the depth of chamfershall not exceed 10% of the nominal socket size, up to and including 1.5mm, and7.5% for larger sizes. This is determined by measuring the depth of penetration ofa NOT GO socket gage.

74

TABLE 48 METRIC ALLEN WRENCHES AND BITS

TABLE 48 DIMENSIONS (2)

0.70.91.31.5

22.5

34

568

10

12141719

22242732

36

W Y B C R L K

NOMINALWRENCH

ORBIT SIZE

HEXAGONWIDTH ACROSS

FLATS

HEXAGONWIDTH ACROSS

CORNERS

0.7110.8991.2701.500

2.0002.5003.0004.000

5.0006.0008.000

10.000

12.00014.00017.00019.000

22.00024.00027.00032.000

36.000

0.6980.8761.2441.470

1.9702.4702.9603.960

4.9605.9507.9509.950

11.95013.93016.93018.930

21.93023.93026.87031.840

35.840

0.7980.9981.4221.690

2.2502.8203.3994.532

5.6906.8289.136

11.470

13.76416.05819.49921.793

25.23427.52530.96936.704

41.292

MAX. MIN. MAX. MIN.

0.7620.9601.3721.640

2.2002.7703.3404.470

5.6306.7609.030

11.340

13.59015.88019.30021.580

25.00027.24030.71036.430

40.900

LENGTHOF SHORT ARM

8111614

16182024

28323640

45566370

8090

100125

140

MAX. MIN.

36

1113

15171823

26303438

43536067

768695

119

133

LENGTH OF LONG ARM

34344445

50566370

8090

100112

125140160180

200224250315

355

MAX. MIN.

69717578

8390

100106

118140160170

212236250280

335375

--

-


MAX. MIN.

0.080.100.140.14

0.140.140.180.24

0.300.360.490.62

0.760.851.041.16

1.361.491.681.99

2.25

RADIUSOF

BEND

LENGTHOFBIT

1.51.51.51.5

2.02.53.04.0

5.06.08.0

10.0

12.014.017.019.0

22.024.027.032.0

36.0

----

----

----

----

--

100.0100.0

100.0

28283943

48536066

768695

106

119133152171

190213238300

338

MIN.

Bits smaller than 27mm are available, but lengths have not been standard-ized.

NOTES FOR TABLE 48

1. ENDS. Each end shall be perpendicular to the axis of the respectivearms of the keys and the longitudinal axis of bits within 4° and the edgesmay be sharp, radiused or chamfered at the option of Holo-Krome, thechamfer not to exceed K.

2. ANGLE OF BEND. The angle of bend between the axis of the shortarm and the axis of the long arm shall be 90°, ±2°.

± 1.5

63656976

818697

102

114136155164

206229242271

325364

--

-

CHAMFERLENGTH

MAX.

3. PLATED PRODUCT. For plated wrenches and bits, all dimensions arebefore plating.

4. INTERCHANGEABILITY. The user is cautioned that ISO metric keysand bits of the same nominal size may not be able to perform adequatelydue to variations in size tolerances which may cause reaming. The use ofAllen Metric Hexagon keys and bits is strongly recommended.


75

TABLE 49 METRIC ALLEN SPLINE KEYS AND BITS

TABLE 49 DIMENSIONS (2)

0.8381.2191.5241.829

2.4382.8193.3783.683

4.2674.648

5.46866.375

7.3919.449

11.53215.113

15.74817.72920.066

M W N B C R K

NOMINALKEYOR

BIT SIZE

MAJORDIAMETER

MINORDIAMETER

0.8381.2191.5241.829

2.4382.8193.3783.683

4.2674.648

5.46866.375

7.3919.449

11.53215.113

15.74817.72920.066

0.8131.1941.4991.803

2.4132.7943.3273.645

4.2164.6105.4486.337

7.3539.411

11.49415.075

15.68517.66620.003

0.6350.9651.2451.575

2.0072.3882.8963.150

3.6584.0134.6745.436

6.2487.8749.576

12.700

13.31015.06217.120

MAX. MIN. MAX. MIN.

0.6350.9651.2451.575

2.0072.3882.8963.150

3.6584.0134.6745.436

6.2487.8749.576

12.700

13.31015.06217.120

Bits are available, but lengths have not been standardized.

NOTES FOR TABLE 49

1. ENDS. Each end shall be perpendicular to the axis of the respective arms ofthe keys and the longitudinal axis of bits with 4° and the edges may be sharp,radiused, or chamfered at the option of Holo-Krome, the chamfer not to exceed K.

2. PLATED PRODUCT. For plated keys and bits, all dimensions are beforeplating.

4666

6666

6666

6666

666

NO.OF

SPLINES

WIDTHOF

SPACE

0.3560.3300.4060.483

0.6100.7110.8640.902

1.0411.1181.3971.664

1.9692.4773.0103.708

4.1024.5855.017

MAX. MIN.

0.3300.3050.3810.457

0.5840.6860.8130.864

0.9911.0801.3591.626

1.9302.4382.9723.670

4.0394.5214.953

LENGTHOF

SHORT ARM

7.92511.12515.87516.662

17.85619.05020.24421.438

22.63123.82526.18728.575

30.96334.13837.31343.663

46.83846.83850.013

MAX. MIN.

3.1756.350

11.91311.913

13.10614.27515.46916.662

17.85619.05021.43823.825

26.18729.36232.53738.887

42.06242.06245.237

LENGTH OF LONG ARM

33.32533.32544.45046.838

50.01353.18856.36359.538

62.71365.88872.23878.588

84.93897.638

110.228135.738

148.438148.438161.138

MAX. MIN.

----

--

92.86397.638

102.388107.163116.688126.213

135.738154.788173.838211.938

230.988--


MAX. MIN.

0.0760.1020.1520.203

0.2030.2290.3560.381

0.4060.406

-0.610

0.7620.8131.1181.270

1.3461.3971.778

RADIUSOF

BENDCHAM-

FER

----

--

88.11392.863

97.638102.388111.913121.438

130.963150.013156.363207.163

226.213--

1.5751.5751.5751.575

1.9812.3883.1753.175

3.9623.962

-5.563

6.3507.9259.525

12.700

12.70014.27515.875

28.57528.57539.67542.062

45.23748.41251.58854.763

57.93861.11367.46373.813

80.16392.863

105.563130.963

143.663143.663156.363

MAX. MIN.

3. SOFT CONVERSION. The spline keys and bits are soft conversions from theinch system, and are therefore interchangeable with Inch product.

76

TABLE 50 HOLO-KROME METRIC DOWEL PINS

TABLE 50 DIMENSIONS OF METRIC DOWEL PINS

1.52

2.53

4568

1012162025

A B C R LT

NOMINALSIZE OR

NOMINAL PINDIAMETER

STANDARDSERIES PINS

OVERSIZESERIES PINS

1.5082.0082.5083.008

4.0085.0086.0098.009

10.00912.00916.00920.00925.009

1.5032.0032.5033.003

4.0035.0036.0038.003

10.00312.00316.00320.00325.003

1.5302.0302.5303.030

4.0305.0306.0318.031

10.03112.03116.03120.03125.031

MAX. MIN. MAX. MIN.

1.5252.0252.5253.025

4.0255.0256.0258.025

10.02512.02516.02520.02525.025

NOTES FOR TABLE 50

1. POINT LENGTH. The point length is decreased and the point angle increased onshort dowel pins.

2. EFFECTIVE LENGTH. The effective length (that portion of the pin between thestart of the point angle and the radius point of the crown) on short dowel pins shallnot be less than 75% of the overall length of the pin. For short pins, it may benecessary to deviate from the specified dimensions by reducing the crown radius orheight, and increasing the point angle, or both.

3. STRAIGHTNESS. Dowel pins shall be straight over the effective length within anaccumulative total of 0.013mm per 25mm of length for nominal lengths up to andincluding 100, and within 0.05mm total for all nominal lengths above 100.

4. END CONTOURS> The ends of hardened ground dowel pins shall be essentiallyperpendicular to the axis of pin. One end of the pin shall be pointed and the otherend crowned to the dimensions specified in Table 50. On the pointed end, the edgeformed by the surface of point and the end of pin may be slightly rounded or broken.The center of the pointed end may be flat or concave. See Fig. 1. The crownedend shall be essentially flat to convex.

5. POINT CONCENTRICITY. The diameter of the point may be eccentric with thepin diameter to an extent such that the minimum length of point on the pin is no lessthan 0.1mm. See Fig. 1.

Applicable Standards and SpecificationsASME B18.8.5M

POINTDIAMETER

1.41.92.42.9

3.94.95.87.8

9.811.815.819.824.8

MAX. MIN.

1.21.72.22.6

3.64.65.47.4

8.411.415.319.324.3

CROWNHEIGHT

0.60.60.70.8

0.91.01.11.3

1.41.61.82.02.3

MAX.

PIN DIAMETERPOINT ANGLETRANSITION

LENGTH

8888

10101212

1620202525

NOM.

CROWNRADIUS

0.20.20.30.3

0.40.40.40.5

0.60.60.80.81.0

MIN.

77

TABLE 51 HOLO-KROME METRIC SCREW THREAD STANDARDS

0Small

▼Large

EXTERNAL THREADS INTERNAL THREADS

AMOUNTMAJOR

DIAMETERPITCH

DIAMETER

--4-

6-8-

Holo-Krome Metric Product is threaded to the requirements of ANSI/ASME B1.13M, Metric Screw Threads, M Profile, coarse series, with a Tolerance Class of4g6g. Because of the lack of familiarity with the ISO system of tolerance designation, a summary is presented here.

METRIC THREAD DESIGNATIONS AND FITS

ISO Metric threads have a designation system which, like the Inch, designated. Accommodation is provided to vary the amount of toleranceprovides the ability to define a class of fit to meet the degree of precision (tolerance grade) and the location of the toleranc e starting positionnecessary to the joint. (allowance) for both the pitch diameter and the major diameter on external

threads and the pitch diameter and the minor diameter on internal threads.The designation applies to both internal and external threads, and is The chart below illustrates these designations.designed to prevent the possibility of interference fit unless specifically

TOLERANCEPOSITION

(ALLOWANCE)

TOLERANCE GRADE(TOLERANCE)

TOLERANCE GRADE AND TOLERANCE POSITION SYMBOLS USED TO DESIGNATETOLERANCE CLASSES IN ISO METRIC THREADS.

TOLERANCE GRADE(TOLERANCE)

MAJORDIAMETER

PITCHDIAMETER

TOLERANCEPOSITION

(ALLOWANCE)

--4-

6-8-

--45

678-

--45

678-

h

g

e

H

G

-

To illustrate a complete designation, let us use the example M5 x 0.5 5g6g.This delineates a thread 5 millimeters in nominal diameter, with a pitch of 0.5.This is a fine thread, because a coarse thread (0.8) would be omitted from thedesignation. In other words, in common practice a coarse thread would bereferred to as M5 - 5g6g.

The 5g represents the pitch diameter information - a tolerance grade of 5,which is fairly small, and a tolerance position of g, which indicates anallowance for plating has been built into the size. The 6g represents the sameinformation for the major diameter - a somewhat larger tolerance but also witha plating allowance.

78

M1.6 x 0.35M2 x 0.4M2.5 x 0.45M3 x 0.5

M4 x 0.7M5 x 0.8M6 x 1M8 x 1.25

M10 x 1.5M12 x 1.75M14 x 2M16 x 2

M20 x 2.5M24 x 3M30 x 3.5M36 x 4

TABLE 52 EXTERNAL THREAD-LIMITING DIMENSIONS M PROFILE

BASIC THREADDESIGNATION

TOLERANCECLASS

ALLOWANCE,ES(2)

4g6g4g6g4g6g4g6g

4g6g4g6g4g6g4g6g

4g6g4g6g4g6g4g6g

4g6g4g6g4g6g4g6g

MAJOR DIAMETER, D

TABLE 52 EXTERNAL THREAD-LIMITING DIMENSIONS M PROFILE

PITCH DIAMETER, D2

MINOR DIAM. , D1

(FLAT FORM) MAX.

MINOR DIAM., D3(ROUNDED FORM)

MIN.(FOR REFERENCE)

0.0190.0190.0200.020

0.0220.0240.0260.028

0.03200340.0380.038

0.0420.0480.0530.060

1.5811.9812.4802.874

3.8384.8265.7947.760

9.73211.70113.68215.682

19.62323.57729.52235.465

Applicable Standards and SpecificationsANSI/ASME B1.13M, B1.3M

1.4961.8862.3802.874

3.8384.8265.7947.760

9.73211.70113.68215.682

19.62323.57729.52235.465

1.3541.7212.1882.655

3.5234.4565.3247.160

8.99410.82912.66314.663

18.33422.00327.67433.342

0.0400.0420.0450.048

0.0560.0600.0710.075

0.0850.0950.1000.100

0.1060.1250.1320.140

1.2021.5481.9932.439

3.2204.1104.8916.619

8.34410.07211.79713.797

17.25220.70426.15831.610

1.0981.4331.8662.299

3.0363.9044.6376.315

7.9859.656

11.33113.331

16.68820.03025.38630.738

MAX. MIN. MAX. MIN. TOL.

0.20.250.30.35

0.40.450.50.6

0.70.750.81

PROOT RADIUS

0.125P MIN. P

0.0250.0310.0380.044

0.0500.0560.0620.075

0.0880.0940.1000.125

1.251.5

1.752

2.53

3.54

4.55

5.568

ROOT RADIUS0.125P MIN.

0.1560.1880.2190.250

0.3120.3750.4380.500

0.5620.6250.6880.7501.000

79

SIZE DIAMETER (IN.) TPI SIZE DIAMETER (IN.) PITCH (MM) TPI (APPROX.)

INCH SERIES METRIC SERIES

0.30.2

0.350.2

0.40.25

0.450.35

0.50.35

0.70.5

0.80.51.00.75

1.251.0

1.51.25

1.751.25

21.5

21.52.51.5

2.51.52.51.5

32

32

0.055

0.063

0.079

0.098

0.118

0.157

0.196

0.236

0.315

0.393

0.472

0.551

0.630

0.709

0.787

0.866

0.945

1.063

85127

74127

64101

5674

5174

3651

32512534

2025

1720

14.520

12.517

12.5171017

10171017

8.512.5

8.512.5

M1.4

M1.6

M2

M2.5

M3

M4

M5

M6

M8

M10

M12

M14

M16

M18

M20

M22

M24

M27

80

6472

5664

48564048

40443240

32362432

20281824

1624

1420

1320

1118

1016

914

812

0.060

0.073

0.086

0.099

0.112

0.125

0.138

0.164

0.190

0.250

0.312

0.375

0.437

0.500

0.625

0.750

0.875

1.000

#0

#1

#2

#3

#4

#5

#6

#8

#10

1/4

5/16

3/8

7/16

1/2

5/8

3/4

7/8

1"

TABLE 53 DIAMETER/THREAD PITCH COMPARISON

80

MECHANICAL PROPERTIESAND

APPLICATION DATAMETRIC PRODUCT

81

MECHANICAL REQUIREMENTS

MATERIALS

Holo-Krome Metric socket products are made from Alloy Steel, containingone or more of the following alloying elements: chromium, nickel, molyb-denum or vanadium in sufficient quantity to assure that the specifiedstrength properties are met after oil quenching and tempering at anappropriate tempering temperature. The requirements for Class 12.9 inASTM F-568 are applied, which is parallel to the ISO specification 898Part I for strengths of fasteners.

HEAT TREATMENT PRACTICE

Holo-Krome Metric socket screw products are hardened and tempered inatmospherically controlled furnaces and quenched in oil above thespecified minimum tempering temperature.

HEADING PRACTICE

Screws from M1.6 to M24 are normally Thermo-Forged® to insure propergrain flow and reduced internal stresses. Screws over M24 nominal sizeare hot formed.

MECHANICAL PROPERTIES AND APPLICATION DATA, METRIC PRODUCT

THREADING PRACTICE

Standard metric socket head cap screws up to M36 can be rolled at Holo-Krome. For thread lengths longer than standard, or special thread pitches,the threads may be rolled or cut. Set screw threads may be rolled, cut orground.

APPLICATION DATA

Standard Holo-Krome Metric alloy socket products are manufacturedfrom alloy steels designed to obtain the optimum performance character-istics for each product.

Holo-Krome Metric socket screws are Thermo-Forged to insure optimumgrain flow without causing fractures, bursts or strain-hardening of theparts. The forming process allows grain lines to flow through the part forgreater part strength and head integrity. Socket walls are smooth and flatand the bottom of the socket does not have broaching chips that reducesocket depth and create a possible starting point for corrosion. Dimen-sional control is also easier to maintain.

WARNING

It is very important that the users of Socket Products, particularlySocket Head Cap Screws, be aware that the practice in Europe andother metric areas, is not to restrict the manufacture of theseproducts to Property Class 12.9.

In the USA, and in inch module parts, it has been customary that thesocket head cap screw configuration is always made from alloy steeland always to a high strength level, typically 180,000 psi. Metriccountries produce this same configuration in alloy steels in Class10.9 as well, and in Class 8.8 from carbon steel. It is vitally importantthat an assembly designed around Class 12.9 cap screws be puttogether with such screws. Beware of lower strength screws beingsubstituted.

82

NOTES FOR TABLE 54

The Mechanical Properties listed are for standard metric screws tested atroom temperature. In applications where the temperatures are considera-bly above or below room temperature the effect of the temperature on theproperties of the screw must be considered. Short time tensile, creep andstress relaxation should be considered for applications where the tem-perature exceeds 200° C. Lower ductility, impact strength and fatigue lifemust be considered for screws subject to temperatures below -29° C.

The materials and heat treatment used for standard Metric Holo-KromeAlloy Steel Socket Products were selected to provide products that wouldhave optimum tensile, impact and fatigue strengths. These materials andheat treatments also meet the requirements of both the USA and ISOspecifications for metric products.

Applicable Standards and SpecificationsASTM A 574M

TABLE 54 TENSILE, YIELD, AND SHEAR STRENGTH OF METRIC SOCKET HEAD CAP SCREWS

1.272.073.395.03

8.7814.220.136.6

58.084.3

115157

245353561817

1.552.534.146.14

10.717.324.544.6

70.8103140192

299431684997

1.402.283.735.53

9.6315.622.140.1

63.792.7

126173

269388616897

0.961.572.573.81

6.6310.715.227.7

43.963.986.8

119

185267424618

1.221.993.294.70

8.3913.419.534.8

55.079.1

108142

222327506729

M1.6 x 0.35M2 x 0.4M2.5 x 0.45M3 x 0.5

M4 x 0.7M5 x 0.8M6 x 1M8 x 1.25

M10 x 1.5M12 x 1.75M14 x 2M16 x 2

M20 x 2.5M24 x 3M30 x 3.5M36 x 4

BODY SEC.(kN)

THD. SEC.(kN)

(kN)(kN)

THREADSTRESS

AREATENSILE

STRENGTHYIELD*

STRENGTH

SINGLESHEAR

STRENGTHNOMINAL SIZE

ANDTHREAD PITCH

TABLE 54 METRIC SOCKET HEAD CAP SCREWS, MECHANICAL PROPERTIES

(mm2)

*Determined on machined specimens only

83

NOTES FOR TABLE 55

These are average values for standard Holo-Krome Metric Socket HeadCap Screws, with standard black finish, tested with hardened steel platesand hardened nuts, with the threads and bearing areas lubricated withplain, medium viscosity machine oil.

The relationship between the torque and the induced tension or preload,can be expressed by the empirical formula T=KDP, in which T is thetightening torque in Newton-meters, D is the diameter of the screw in mm,P is the tension in kiloNewtons and K is the torque coefficient. The torquecoefficient is not constant, but varies with the material, surface finish andlubricity of the threads and head bearing surface of the screw and theparts being tightened.

For the condition shown above (standard alloy steel black finished screwsclamping hardened steel parts), K will range from 0.19 to 0.25. Forcadmium plated screws with steel parts, K will usually fall between 0.13and 0.17. For zinc plated screws, K may fall between 0.30 and 0.34. Whenthe thread and head bearing surfaces are covered with certain types oflubricants, or with anti-seize compounds, K can drop to as low as 0.05. Atthe other extreme, combinations of certain materials, such as austeniticstainless steel screws and unlubricated parts, can result in K valuesabove 0.35.

Because the induced tension can vary considerably from one type ofassembly to another, the above data must be used with caution, particu-larly in applications where the control of preload is critical and must beobtained by Torque Wrench method. For such applications, the relation-ship between torque and induced load should be determined experimen-

tally for the actual parts and lubrication practice used.

TIGHTENING TORQUES. At the recommended tightening torques listed,standard Holo-Krome Metric Socket Head Cap Screws, used under theconditions described, will be preloaded to approximately 75% of thetension induced at yield. The bearing stress under the head will beapproximately 530 MPa, so indentation should not occur when theclamped parts are made of steel or cast iron with a hardness equal to orgreater than HRB 85. With softer materials, washers may be requiredunder the heads of the screws to prevent indentation.

In applications where screws are subject to fatigue from dynamic loading,the importance of proper preloading during assembly can not be over-emphasized. The proper preload is especially important for rigid type(metal-to-metal) joints where it has been found that the use of preloadgreater than the dynamic external load will usually eliminate the probabil-ity of fatigue failure. For this reason, the preferred practice for suchassemblies is to preload to 75% of the induced tension at yield.

For flexible type joints, however, and for assemblies exposed to elevatedtemperatures, much lower preloads may be required. No general recom-mendations are possible for the wide range of applications and serviceconditions. Each application must be analyzed individually, because thepreload requirements may vary considerably from one application toanother. Users who desire suggestions for the preload or tighteningtorque to be used for a specific application are invited to contact the Holo-Krome Engineering Department.

TABLE 55 TIGHTENING TORQUE DATA

NOMINAL SIZEAND

THREAD PITCH

M1.6M2M2.5M3

M4M5M6M8

M10M12M14M16

M20M24M30M36

0.340.691.432.48

5.8512.020.348.8

97.5165265413

825142527754875

0.951.502.493.59

6.3610.414.726.5

42.459.882.3112

179258402589

TABLE 55 METRIC SOCKET HEAD CAP SCREWS, TORQUE DATA

TENSIONINDUCED,

(kN)

RECOMMENDEDTIGHTENING

TORQUE(N•m)

84

CARBURIZATION OR DECARBURIZATION

Surface carbon content variations conform to the limits specified in Tablewhen tested in accordance with ASTM A 574M. There should be nocomplete decarburization nor carburization. Carburization or decarburi-zation can only be measured accurately on a screw that has beensectioned on a plane that is parallel to and passes through the screw axis.

DISCONTINUITIES

SOCKET DISCONTINUITIES

Discontinuities in the socket area allowed to a maximum depth of 0.03Dor 0.13 mm (whichever is greater), providing they do not affect theusability and performance of the screw.

Longitudinal discontinuities must not exceed .25T in length. Permissibleand nonpermissible discontinuities are shown in Figure 1.

PERMISSIBLE HEAD AND SHANK DISCONTINUITIES

Discontinuities as defined above are permitted in the location illustratedin Figure 1 to the depths described above, with the addition that peripheraldiscontinuities are permitted a maximum depth = .06D, but not over1.6mm. These discontinuities are permitted providing they do not affectthe usability and performance of the screw. All discontinuities aremeasured perpendicular to the indicated surface.

When the engineering requirments of the application require that surfacediscontinuities must be more closely controlled, the purchaser shouldspecify the applicable limits in the original inquiry and in the purchaseorder.

REJECTION

Rejections should be reported to Holo-Krome within 30 days of receipt ofthe parts, by the purchaser. The rejection may be in writing to thedistributor or directly to the Holo-Krome Sales Department. When nospecial requirements are specified, industry standards such as ASTMA574M will be used as referee documents.

TABLE 56 DECARBURIZATION AND DISCONTINUITY LIMITS

THREAD PITCH

mm

THREAD HEIGHT

H. mm

0.75 H. FROMROOT TO CREST,

MIN. mm

TABLE 56 DECARBURIZATION LIMITS

0.350.40.450.5

0.70.81.01.25

1.51.7522.5

33.54

0.2150.2450.2760.307

0.4290.4910.6130.767

0.9201.0741.2271.534

1.8402.1472.454

0.1610.1840.2070.230

0.3220.3680.4600.575

0.6900.8060.9201.151

1.3801.6101.841

FIGURE 1

85

TABLE 57 MECHANICAL PROPERTIES OF THREADED TO THE HEAD STAINLESS STEEL METRICSOCKET HEAD CAP SCREWS

TENSILE STRENGTH YIELD STRENGTH*SINGLE SHEAR

STRENGTH

(kN) (kN) THREAD SEC. (kN) (N.m)

TIGHTENINGTORQUE

M1.6 x 0.35M2 x 0.4M2.5 x 0.45M3 x 0.5

M4 x 0.7M5 x 0.8M6 x 1M8 x 1.25

M10 x 1.5M12 x 1.75

.841.382.253.35

5.849.4413.424.3

38.656.1

.58*. 83*1.37*2.01*

3.51*5.68*8.0414.6

23.233.7

0.55 0.90 1.47 2.19

3.806.148.72

15.9

25.236.7

0.180.370.761.31

3.106.36

10.825.9

51.787.5

MATERIAL

Standard Holo-Krome Stainless Steel Metric Socket Head cap screws aremade from austenitic (18-8) stainless steel. They withstand all ordinaryrusting, are immune to all foodstuffs, sterilizing solutions, most of theinorganic chemicals, dyestuffs and a wide variety of inorganic chemicals.They resist nitric acid well, halogen acids poorly and sulfuric acidsmoderately.

Holo-Krome Stainless Steel Cap Screws are passivated by immersion ina nitric acid bath subsequent to the last manufacturing operation. This ridsthe surface of contaminants picked up during fabrication that can causesurface staining or rusting.

Holo-Krome Standard Stainless Steel Cap Screws have low magneticpermeability which makes them suitable for electrical applications wherenon-magnetic parts are required.

NOMINAL SIZEAND

THREAD PITCH

*Yield strength for information only-sizes through M5 are tested for torsional strength only per ASTM F738. Values based on ASTM F837M.

NOTES FOR TABLE 57

Tensile strengths given above are for standard stainless steel metricsocket head cap screws tested at room temperatures. When screws areto be exposed to higher temperatures the effect of temperature upon theshort time properties and the possibility of plastic deformation, or creep,should be considered. At 425°C, the tensile strength of standard stainlesssteel screws will be approximately 75% of the room temperature strength,and the screws have good creep resistance. Normally, standard stainlesssteel screws are not used above 425°C, because above this temperature

the material is subject to intergranular corrosion.

The property class designation for Holo-Krome Stainless Steel MetricCap Screws is A1-70, as defined by ASTM F738.

Applicable Standards and SpecificationsASTM F837M

TABLE 57 HOLO-KROME STAINLESS STEEL METRIC SOCKET HEAD CAP SCREWS

86


Standard Metric Holo-Krome Alloy Steel Button and Flat CountersunkHead Cap Screws are manufactured from Holo-Krome analysis highgrade alloy steel, hardened and tempered to provide the followingmechanical properties.

The tensile strength of the screws, because of head configuration arebased on 980 MPa as shown in ASTM F 835M.

Tensile Strength * .............................................. 1220 MPaYield Strength* ................................................... 1100 MPaElongation in 2 inches* ...................................... 8%Reduction of Area* ............................................. 35%Hardness ............................................................ 38 Rockwell C min.*Apply to cylindrical test specimens only.

THREADSTRESS AREA

(mm2)

TENSILESTRENGTH

(kN)

SINGLE SHEARSTRENGTH

(THREAD SEC.)(kN)

5.038.78

14.220.1

36.658.084.3

157245

M3 x 0.5M4 x 0.7M5 x 0.8M6 x 1

M8 x 1.25M10 x 1.5M12 x 1.75M16 x 2M20 x 2.5

4.938.60

13.919.7

35.956.882.6

155240

3.816.65

10.715.2

27.743.963.9

119185

TABLE 59 TIGHTENING TORQUE - N•m

22.534

568

1012

M3 x 0.5M4 x 0.7M5 x 0.8M6 x 1

M8 x 1.25M10 x 1.5M12 x 1.75M16 x 2M20 x 2.5

1.252.95.9

10

244884

207

BUTTON HEAD

1.853.46.9

12

285699

246400

Torque to tighten screw with key, not by turning nut.

These torques apply to standard black screws in rigid joints, when torqued with standardhex keys or bits.

TABLE 58 HOLO-KROME METRIC BUTTON HEAD ANDFLAT COUNTERSUNK HEAD SOCKET CAP SCREWS

NOTES FOR TABLE 58

BUTTON HEAD CAP SCREWS ARE DESIGNED FOR LIGHT FAS-TENING APPLICATIONS ONLY, SUCH AS SHEETMETAL COVERS,PLASTIC GUARDS, ETC. THEY SHOULD NOT BE USED IN CRITI-CAL HIGH STRENGTH APPLICATIONS WHERE SOCKET HEADCAP SCREWS SHOULD BE USED.

The mechanical properties listed are for screws tested at normal roomtemperatures. In applications where the temperature are considerably

above or below room temperature the effect of the temperature on thescrew strength must be considered. Short time tensile, creep andstress relaxation should be considered for applications where thetemperature exceeds 204° C. Lower ductility, impact strength andfatigue life must be considered for screws subject to temperaturesbelow -29° C.

Applicable Standards and SpecificationsASTM F 835M

NOMINALSIZE AND THREAD

PITCHMM

NOMINALSIZE AND THREAD

PITCHMM

MAX. TIGHTENINGTORQUE

(N.m)HEX KEY SIZE

(mm)

MAX. TIGHTENINGTORQUE

(N.m)

FLAT COUNTERSUNKHEAD

TABLE 58 HOLO-KROME METRIC BUTTON HEAD AND FLAT COUNTERSUNK HEADSOCKET CAP SCREWS

87

TABLE 60 HOLO-KROME METRIC SHOULDER SCREWS

SHOULDER SCREWS

Shoulder screws, commonly referred to as stripper bolts, are used in avariety of applications. In die sets, they can be used for stripper springsand as guides. They are used as pivots for linkages, pulleys andsprockets and as hinges.

Holo-Krome metric socket shoulder screws are made from alloy steel.Holo-Krome step grinds the shoulder and roll thread diameter in oneoperation after heat treatment to assure concentricity.


Tensile Strength ................................................. 1100 MPa*Hardness ............................................................ 36 Rockwell C min*Based on stress area of the thread neck.

THREAD NECK

THREAD NECK SECTIONTENSILE STRENGTH

(kN) SHOULDER

7.010.018.930.7

45.387.1

137

21.632.751.386.8

13.1206322

** It is recommended that tightening torque be limited to these values when screws are to be tightened or loosened with standard keys or bits.

HEX KEY SIZE(mm)

TABLE 60 MECHANICAL PROPERTIES

TIGHTENING TORQUE**(N.m)

3456

81012

6.9122856

99250400

NOMINAL SHOULDERDIAMETER

(mm)

NOMINAL THREADSIZE(MM)

6.58

1013

162025

M5 x 0.8M6 x 1M8 x 1.25M10 x 1.5

M12 x 1.75M16 x 2M20 x 2.5

11.715.228.651.1

75.5145230

SINGLE SHEAR STRENGTH(kN)

88

TABLE 61 HOLO-KROME METRIC SOCKET SET SCREWS - AXIAL HOLDING POWER

1.622.53

4568

1012162024

.7

.91.31.5

2.02.53.04.0

5.06.08.0

10.012.0

0.10.20.61.0

2.14.77.7

17.8

3555

125250425

4487

306880

1570240033805800

936013,30023,10034,70051,500

NOTE:The values above have been developed experimentally by assemblingsteel collars to cold finished steel bars (Rockwell B 80-100) withstandard Holo-Krome Metric alloy steel Cup Point Set Screws with theblack finish. The set screws were all as long as or longer than theirnominal diameter. The axial holding power listed above was theaverage force required to cause .125 mm movement of the collar alongthe shaft after tightening the set screw to the listed torque. For specificapplications, values may vary as much as ±30 percent from valuesshown.

Giving a cup point a relative holding power of 1, the holding power of acone point is 1.07, a flat point or dog point 0.92 and an oval point 0.9.

For torsional holding power, multiply the axial holding power value bythe shaft radius.

SET SCREW HOLDING POWER

AXIAL HOLDING POWER OF CUP POINT SET SCREWS (ALLOY STEEL)

INTRODUCTION. Set screws, unlike most other fasteners, are basi-cally compression fasteners. Because studies made of tension fasten-ers do not apply and because of the complex nature of this type of joint,the holding power of a set screw is more difficult to predict and controlthan the typical cap screw joint. Many variables introduced by aparticular application may affect the holding power performance of a setscrew. It is therefore important for the designer to understand set screwholding power and the nature of the variables involved when designinga set screw joint.

HOLDING POWER. The forces which a set screw assembled joint cantransmit or withstand without relative displacement of the two parts isa measure of the holding power of the screw. This holding power canbest be described in terms of the forces acting to cause relative

movement between the assembled parts.

1. AXIAL HOLDING POWER. Using a simple shaft collar applicationas an illustration, the force acting on the collar to move it along the shaftis called the axial force. The ability of the set screw to withstand thisforce without relative displacement is called its Axial Holding Power.

2. TORSIONAL HOLDING POWER. Using a shaft pulley or gearapplication as an example, the force (F) acting to rotate or slip the pulleyaround the shaft is frequently called the rotational force. The ability ofa set screw to withstand these forces tending to rotate the part on theshaft without relative movement of the two parts is called its TorsionalHolding Power.

NOTE. For further discussion of holding power see page 38.

NOMINAL SIZE

(mm)

Applicable Standards and SpecificationsASTM F 912M

HEX KEY SIZE

(mm)

TIGHTENINGTORQUE

(N•m)

AXIAL HOLDING POWER

(N)

89

TABLE 62 METRIC ALLEN WRENCHES AND BITS

TABLE 62 METRIC ALLEN WRENCHES

MECHANICAL APPLICATION DATA

NOMINALSIZE

mm

TORQUERATING

(N.m)

0.70.91.31.5

22.534

56810

12141719

22242732

36

0.10.20.61.0

2.14.77.7

17.8

3557

126252

420670

11801670

2450320043006800

10,000

CAPSCREWS

FLATCOUNTERSUNK

HEAD CAP SCREWSBUTTON HEADCAP SCREWS

NOMINAL SCREW SIZES

SHOULDERSCREWS

SETSCREWS

————

M3M4M5M6

M8M10M12M16

M20———

———

————

M3M4M5M6

M8M10M12M16

————

———

————

——6.58

10131620

25———

———

M1.6M2M2.5M3

M4M5M6M8

M10M12M16M20

M24———

———

TORQUE RATING-Standard Allen Wrenches cut into bits for use intorque wrenches will transmit the above torques. These torque valuesare 90% of average torque required to develop a permanent visibletwist in bits which have 25mm of hexagon exposed between the torquewrench and the socket. These are also the torque values which keystransmit when the short arm is inserted in a socket and the long arm is

deflected or bent through an angle of 25 to 30° by the application of forcenear the end of the long arm.



Standard Allen Wrenches and Bits are manufactured from Holo-KromeAlloy Steel, hardened by quenching in oil from the hardening tempera-ture and tempered to a hardness range of HRC 50-57 for keys 2.5mmto 12mm, HRC 45-53 for 14mm and larger, and Knoop 565-685 forsizes 2mm and smaller, to provide the following torsional properties.

———

M1.6

M2.5M3M4M5

M6M8M10M12

M14M16M20M24

M30—

M36

NOMINALSIZEmm

0.70.91.31.5

22.534

56810

12141719

222427

90



Standard Holo-Krome Metric Dowel Pins are manufactured from Holo-Krome analysis High Grade Alloy Steels heat treated to a core hardnessof HRC 47-58 for toughness and strength and a surface hardness of HRC60 minimum for wear resistance.

CAUTION: Holo-Krome recommends dowel pins be inserted byapplication of a constant pressure, with the pin being shielded in case offracture. A striking force can cause the pin to shatter.

1.5 2.0 2.5 3.0

4.0 5.0 6.0 8.0

10.012.016.020.025.0

NOMINALSIZEmm

MINIMUMCASE DEPTH

mm

SINGLESHEAR

STRENGTH(kN)

0.250.250.250.25

0.250.380.380.38

0.380.380.380.380.38

1.853.35.157.4

13.220.629.752.5

82.5119211330515

DOUBLE SHEARSTRENGTH

(kN)

3.7 6.6 10.3 14.8

26.4 41.2 59.4 105

165 238 422 6601030


RECOMMENDED HOLE SIZEmm

1.5002.0002.5003.000

4.0005.0006.0008.000

10.00012.00016.00020.00025.000

1.4871.9872.4872.987

3.9874.9875.9877.987

9.98711.98715.98719.98724.987

MAX. MIN.

fasteners standards

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