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T H E M E R I C A N O C I E T Y OF M E C H A N I C A L N G I N E E R S

U n i t e d n g i n e e r i n g e n t e r 3 4 5 East 4 7 t h S t r e e t e w o r k ,

N. Y.

1

O0

17

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i A S M E

SI-L 82

m

0759670 0083944 5

m

. . , I

-.

ASME GUIDE

SI

- 1

ASME

0rientati.on.and

Guide

for Use of

SI

(Metric) Units

NINTH

ED

March 24,1982

llTlON

T H E M E R I C A N O C I E T Y

OF

M E C H A N I C A L N G I N E E R S

U n i t e d n g i n e e r i n g en t e r4 5 E as t 4 7 t h t r e e t e w o r k ,

N,

Y.

1

O 0 1



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No

part of this docúment may

e

reproduced in any form ,

in an electronic retrieval system or otherwise,

without the prior written permission

f

the publisher

/

Copyright

O

1982

THE AMERICAN SOCIETY OF MECHA NICAL ENGINEERS

All Rights Reserved

Printed in U.S;A. . .



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B O A R D

ON

METRICATION

J.

G

L a n g e n s t e h , Chairman

Kurt Wessely,

secretary

W,

P Adkins

J.

T.

Blackburn, Jr.

J. S ,

Castorina

O

J.

Fisher

W. P Gobel l ,

Jr .

F. T, Gut m a nn

Carl Hand en

F.

R . Jackson

R. G . J o b e

J . G. Langenste in

Samuel Leland

J. B. Levy

R. J. Mann

W . G . McLean

J.

W.

Murdock

D. H .

Pai

J. J, Pohl, Jr.

P . C.

Q u o

K.

.

Simila

C ,

E.

S m i t h

A. M . S m o l e n

D. H , White

C. J . Wilson

B .

D.

Ziels



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Con

ents

SECTIONS

1

Backgraund and Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2. History of the International System . . . . . . . . . . . . . . . . . . . . . . 3

3 . SIBaseUnits

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4

4. SupplementaryUnits

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5

5 . PreBxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

7. Rules for Use of SIUnits in ASME Publications . . . . . . . . . . . . . . 9

8

. Conversion and Rounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

9

.

Dimensioning

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 6

11. Units Accepted Temporarily. . . . . . . . . . . . . . . . . . . . . . . . . . . .

18

6

. The Coherence o f Derived Units

in

SI

. . . . . . . . . . . . . . . . . . . . . 7

10. Units Outside the International System

....................

17

12. Units No t t o be Used in ASME Documents.

. . . . . . . . . . . . . . . . .

9

13

.

SIUnits for ASME Use.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21

14. Introducing SIUnits in ASME Publications

. . . . . . . . . . . . . . . . .

3

15 Introducing SI Units

in

Tables

. . . . . . . . . . . . . . . . . . . . . . . . . .

24

16. Methods of Reporfing

SI

Equivalents for Existing Standards Under

Revision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4

TABLES

1

SI

Base Units

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5

2. SI Unit Prefwes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4 . Some Derived Units Withovt Names . . . . . . . . . . . . . . . . . . . . . . 9

S

.

Units

in

Use With the In teq atio na l System . . . . . . . . . . . . . . . . . 8

6

Units Used With t h e International System in Specialized Fields

. . . 1 8

7. Units To Be Used With the International System for a Limited Time

.

9

8. CGS Units w ith Special Names . . . . . . . . . . . . . . . . . . . . . . . . . 0

10

. List o f

SI

Units for ASME Use.

. . . . . . . . . . . . . . . . . . . . . . . . . 21

APPENDICES

.

Appendix1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Appendix2

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26

Appendix3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Appendix4

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29

Appe4dix5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0

Appendix7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . .

. . . . . 2

Appendix8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

33

Appendix9

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

34

Appendix10

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

36

3

.

Derived Units With Names

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9

9 . Other Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Appendix6

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

31

V



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ASME

Guide

SI-1

ASME

Orientat ion and Guide

for

Use of

S I (Metric) Un i t s

Ninth Edition

March 24, T982

SECTION

l .

BACKGROUND AND POLICY

The 1967 Regional Adm inistrative Conference passed th e following resolu-

tion: “Form a working comm ittee t o propose and implement constructive

solutions to problems associated with conversion

to

the metric system.”

In 1968 a Special Committee on Metric Study was established by the

Council of ASME.

This

committee has held a series of m eetings which culmi-

nated in thefollowing Council policy:

1. 197O:TheASME anticipates th e displacement of the usage of

US.

customary units by the usage

of.SI*

(metric) units i n- m an y fields.

2 1970-The ASME believes that b oth

U.S.

customary and the SIsystems

of units, m odules, sizes, ratings, etc., will cont inue in use in th e oresee-

able future.

31 1970-Because of the increasing international com mitment 0f.U.S.engi-

neering and U.S. industry and commerce, the ASME recognizes the

need for an accelerated growth in the capability in and between both

-systems by the mechanical engineering profession.

4.

1970-The ASMEwill encourage and assist the development of this

“dial capability” by specific and positive actions, including the fol-

(a)

Contribute to the continuing development

of

the International

(b) Develop and dissemina te data t o facilitate conversion and insure

(c) Provide and promote education in the fundamentals and applica-

. lowing:

System, particularly t o meet engineering requirements.

correspondence between the

U.S.

customary and

SI.

tion

of

bo th systems.

*International

System

1


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82 00839LI9 Y

1 ~ ~~ ~~~ ~ ~~~~~~~~ ~ ~

(d) Encourage and guide the’use or inclusion

of

SI units as appropriate

(e)Work with ANSI to develop and implem ent U.S. national poli-

5

1970-The ASMEwill continue to support the National Bureau

of

Standards of the -Department of Comm erce in its “Metric Study,”

pursuant to Public Law 90472.Its.membership will be kept informed

of all significant NBS actions.

6 .

1972-For the purpose of moving forward the ASME will maintain

close liaison with legislative activities concerned with increased use of

the International Metric System (SI).

7. 1973-The Society encourages th e initiation of a coordinating volun-

tary national program o f conversion t o

SI

usage.

8. 1973-As of July 1 , 1974, SI units (in addition to any o ther units) will

be required in ASME papers and in revised, reaffirmed and new engi-

neering standards.

9. 1974-The ASME will cooperate fully with he American Nationa l

Metric Council ‘(ANMC), and other societies and agencies to minimize

duplication of effort..

.

1 0 . 1 9 7 7 4 1 units shall be included in standards at the appropriate time as

determined by industry, government, public and society needs consis-

tent with na tio nd plans for coordinating and managing development of

SI standards.

.

The ASME Metric Study Committee maintains contact with the National

Bureau of Standards and various technical societies’involved in the change to

SI and has developed educational material and reports t o th e membership.

The committee also developed sociefy positions on me tric legislation. The

U.S. Metric Study Report was submitted tó Congress for study and imple-

mentation in July, 1971.

This

report -recognized th a t “ëngineering‘standards

have served as a keystone in our domestic industrial developm ent, as they

have in other industrialized nations.” It notes that only a small portion of

U.S. standards are coordinated by the American National Standards Institute

(ANSI)which represents the -U;S. on he nternational Electrotechnical

Comm ission (IEC) and in the International Organization for Standards (ISO).

Many IEC and IS 0 recommendations are not com patible withU.S. Standards,

The reportfurther states: “If

U.S.

practices aré t o - b e reflected in nter-

national recommendations, active participatiob on the drafting committee

is essential.” With the trend to use the International System of Units “further

national standards which d o not include SI units are

ñot

likely t o receive due

consideration

in

the development of international standards.”

Since dimensional specifications in different metric countries are incom-

patible as frequently as those in countries using th e inch unit for measure-

ment “a change-to SI doès not by itself make standards.compatible.” T he re-

port continues, “a few dimensional specifications based on the nch and U.S.

in Codes and S tandards and other ASM,E publications.

cies regarding nternational standardization.

2



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A SM E

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0759670

0083950 O

engineering .practices are used internationally and have been incorporated in

IEC and IS 0 recomm endations. Likewise, there are a few specifications based

on metric units used throughout the world including the U.S.” The report

states that a change in bo th metric and nonmetric countries is required to

achieve international standardization. A review of practices incorporated in

standards could result in new practices and standards “which

w i l l

conserve

raw m aterials, improve the quality of products and reduce costs.”

ASME is a charter subscriber to the American National Met& Council and

several members of.the ASME Metric Study Committee serve or have served

on the ANMC .Board of Directors, Metric Practice Comm ittee, and sector

committees.’

I ~. - ~ ~~ ~ ~ ~

SECTION 2. HISTORY OF THE INTERNATIONAL SYSTEM

As our technology grew

in

the nineteenth century, it became apparent

there was a great need for international standardization and improvements in

the accuracy of standards for unitsof length ahd mass. As a result, in

1872

an

international meeting was held in France and was attended by representatives

of

26

countries including the United States. Out of this meeting-came the

international trea ty, the Metric Convention, which was signed by17 countries

including the United States in

1875.

The treaty:

(a) Set up-metric standards for length and mass.

’

.

-

(b) Established the International Bureau of Weights and Measures (abbre-

.

viated from the French as BIPM:-PM for French “Poids e t mesures”

meaning “weights and measures”).

(c) Established the General Conference of Weights and Measures (CGPM)

which meets every six years.

(d) Set

up

an International Committee of Weights and Measures

( O M )

which meets every two years and which implements the recommenda-

tions of the General Conference and directs the activities bf the Inter-

national Bureau. The

1960

meeting

of

CGPM consisting then of 40

members, modernized the metric system. This revision is the Interna-

tional System of Units (SI)*. The expression used hereafter “SI

Units,” “SI Prefures” and “supplementary units” are the results of

Recommendation 1 (1960) of the CIPM. The sixth base unit.listed in

Table

1

was proposed as a Resolution by CIPM in.

1969

andwas

adopted by the 14thCGPM in 1971,

*“LeSysteme nternationald’Unit&,” 1970, OFFILIB,

48

rueGay-Lussac,

F. 7 5

Paris

S

(revised edition

1972).



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’ ASNE

SI-1 8 2 m O759670 0083953 2 m

~~ ~~

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SECTION 3.

SI

BASE UNITS

The following are definitions of the seven base units:

(a) The “meter”* is the unit of length which s the length. equal to

1 65 0 763.73 wavelengths in vacuum of the radiation corresponding

to the transition between levels 2p, and 5d5 of th e krypton-86 atom.

h

conformance with

SI

practice the number of wavelengths s

written

in

groups of three digits

without

commas.)

.

(b) The “kilogram” is the unit of mass which is equal to mass of the

international prototype kilogram, located at the-BE” headquarters.

(c) The “second”

is

the unit

of

time which is the duration

of

9 192

631

770

periods of the radiation corresponding to the transition between the

two hyperfine levels of the ground state of th e cesiu m1 33 atom .

(d) The “ampere” is the unit

of

electric current which is that constant

current which, if maintained in two straight parallel conductors of

infini te length, of neghgible circular cross section, and placed 1meter

apart in vacuum, would produce between these conductors a force

equal

to

2 X newton per meter of length (newton is a derived

(e). The “kelvin” is the unit

of

thermodynamic temperature which is

the

fraction 1/27 3.16 of the . thermodynamic temperature of the triple

point of water. The SI unit of temperature is the kelvin. The Celsius

temperature (previously called Centigrade) is the commonly used

scale for temperature measurements, except for some scientific work

where the thermodynamic scale

is

used. A difference

of

one degree on

the Celsius scale equals one kelvin. Zero

on

the thermodynam ic scale

is 273.15 kelvins below zero degreeCelsius. The degree symbol is

associated with Celsius temperature (to avoid confusion with the un it

C

for coulomb) bu t no twith t he kelvin. Thus 20°C = 293

-15

K on

the

thermodynamic scale but a temperature difference of 1°C

= 1

K.

See

Appendix 9.)

( f )

The “mole” is the unit

of

amount of substance

of

a system which

contains as many elementary entities as there are atoms in 0.012

kilogram of carbon 12.

(g)

T he “candela” is the unit of luminous intensity in the perpendicular

direction,

of

a surface of 1/600

O00

square meter of a blackbody at

the temperature

of

freezing platinum under a pressure 101325

newtons per square meter.

unit).

The symbols for these base units are given in Table 1. Note that symbols

are never pluralized, are never written with a period, and the practice with

*Meter-This

is

the spelling recommended by the ASMEMetric Study Committee

for

use in ASME publications. The alternafe spelling, “metre,” may be used at the discre-

tion

of

th e author.

4



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ASME

SI-1 8 2 0759670 0083952

4 W

.

-

~ ~ ~

~~~-

~~~ ~ ~~~

respect to upper and lower case modes m us t be followed withou t exception.

Refer to

ANSI

X3.50 or

I S 0 2955

for proper symbols for use

in

limited

character sets (availability

of

only upper case letters or only lower case let-

ters).

TABLE I -SI BASE UNITS’

~.

Quantity

Unit Name Unit Symbol”

~ ~

Length

meter m

Mass

kilogram**g

Time

second

S

Electric current

ampere

A

Thermodynam ic temperature

kelvin K

Amount of substance

mole mol

Luminous

intensity candela cd

‘Special Publication 330, p. 6, National Bureau

of

Standards. (See Appendix

8.)

*In general, roman (upright typé) lower case is used for symbols of units; hówever, if

the

symbols

are derived from proper names, capital

roman

type

i s

used

for

the f i s t

letter.

**The kilogram is the

o n l y

base unit with a prefix.

SECTION

4.

SUPPLEMENTARY

UNITS

The General Conference has no t yet classified certain units of the Ïntei-

national System under either base units or derived units. These

SI

units are

assigned to the third class called “supplementary units” and may be regarded

either as base units or as derived units,

The tw o supplementary. units a re the radian for plane angle (symbol rad)

and

the

teradian for

solid

angle.(symbol sr),

SECTION 5. PREFIXES

Decimal

multiples and submultiples

of

th e SLunits are formed by means

of the prefixes detailed in Table

2

on nex t page. Only one multiplying prefix

is

applied at öne time o

a

given unit,

cg. ,

nanometer (nm), not millimicrome-

ter (mpm).

5



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C o p y r i g h t A S M E I n t e r n a t i o n a l

P r o v i d e d b y I H S u n d e r l i c e n s e w i t h A S M E

L i c e n s e e = A b e i n s a E n g i n e e r i n g / 5 9 8 9 3 0 4 0 0 1 ,

U s e r = L o z a O r o z c o ,

A d r i a n a

N o t f o r R e s a l e ,

0 3 / 1 3 / 2 0 1 4 2 3 : 4 7 : 5 2 M D T

N o r e p r o d u c t i o n o r n e t w o r k i n g p e r m i t t e d w i t h o u t l i c e n s e f r o m I

H S

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ASME SI-L 82

m

O759670 0083954 8

m

The symbol of a p r e f a is considered to be combined with the unit symbol

to which it is directly a ttached, forming with it a new unit symbol which can

be raised t o a positive QI negative power and which can be combined with

other unit symbols to form symbols for compound units.

~~

___

Examples:

1

mm3 = (IV3m)3

=

m3

1 mm2/s= ( lu3m)'/s = 10 ~ m2 s

1 ns-1 = 1 0 9

s)-1

= 109 S-1

When expressing a quantity by a numerical value and a specific unit, it is

desiiable inmost applications to select a multiple or submultiple of the

unit which results

in

a numerical value between 0.1 and

1000

It is desirable, however, to carry the multiplesand .sub.multiples to greater

or smaller numerical values where the predominant usage is dictated by this

rule, eg ., mechanical design uses: mm.

Example:

7950 mm instead of 7,950m

Note: In text and tables, if a numerical value

is

less than one, a zero

shall precede the decimal point.

The use of prefmes representing

10

raised to a power which is a multiple

of 3 is especially recommended in IS0 10oO.* The use of prefixes in the

denominator

of

derived units should be avoided,

SECTION 6. THE COHERENCE

OF DERIVED

UNITS

IN

SI

SI comprises the seven base units listed in Table 1

,

he two supplementary

units radian and steradim, and any number of units derived from the base

units, supplementary units, or other derived units. Certain derived units have

special names, See-Table 3,

I t

is a fundamental and convenient feature of SI that the base units, supple-

men tary units and derived units form a coherent system. Derived units are

algebraic expressions in terms of powers of the base units, and

al l

numerical

factors are unity.

In

the inch-pound system, by contrast, a great

many

numer-

ical factors come into play when units are derived from each other,

or

even

when they are compared with one another, The difference between coherence

and lack of coherence can be shown by comparing the units of power in the

two systems.

*See Appendix 8 .

7



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power

=

work per unit of time

=

(kg.*m2*s-2)

S = k g m 2

This derivation applies. to mechanical and electrical as wellas thermal

power. The unit of power is the watt , Inmost applications, power outp ut or

input will be expressed inkilowatts or megawatts,

In the customary system, mechanical poGer is. measured

in

horsepower,

therm&po.wer

in

British Thermal Units, and electrical power

in

kilowatts.

These.units are related to each other by the.following:

.

. .

1 h p

=

33 O00 ft-lb

500

ft-lb

-

2545 Btu

-

42.42.Btu =

746 watts

=

- -

min sec hr

min

No te the lack o€consistency in the unit

qf

ime and th e many numerical

factors. The unit for electrical power

is

the samein the nch-pound system and

in

SI.

The numerical relationships incorporate well-known empirical factors.

Table

3

sho.ws SI derived units with their names, symbols, and formulas,

and for each derived unit an expression

in

terns of base and supplementary

units. Note tha t every unit name is.speUed with a lower case fi s t letter ; upper

case

is

t o b eused only at thebeginning of a sentence. The rule for capitalka-

tion

of unit symbols is as follows: if a unit is named for a person, the first

letter

of

th e symbol.

is

capitalized, as

in

V

fo r volt or Hz for hertz; otherwise

the unit symbol is in lower case, as in lm for lumen or

lx

for lux. The e i i p

tion is the symbol

L

for liter.

This

rule applies to all SI units.

. .

Copyright ASME International

P id d b IHS d li ith ASME Li Ab i E i i /5989304001 U L O Ad i

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` ` , ,

` ` , , ,

` , ,

` ` ` , , ,

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: A S M E SI-L 8 2

m

0759670008395b

L

m

TABL E 3-DERIVED UN ITS WITH NAMES

~

Expression

i n Terms

Ouantity Name Sym bol Formula of SI Base Units

Frequency hertz

HZ

11s

or S”?

Fórce newton .

N

m -kg *s“ me kg S-’

Energy, work -joule

J

N*m m2*kg.

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- ,

0759670

o u t l j y s ’ t

3

,

engineers and scientists to denote- he force of local gravity. Although this has

been the meaning accepted for scientific use, the term is also widely used to

enote. other closely-related forces and to denote mass.

This fact is intertwined with the past use o f the same names as units of

both force and mass (cg., lbf and lbm , and kgf and kg).

Both ambiguities lead to communication difficulties, Therefore, the use

of the term weight isdiscouragedn ASME technical communications.

Either “force of gravity

on ’

or “gravity force

on”

will be far less likely to

be misinterpreted than “weight of”.

Length.measurements in technical papers and publications should be ex-

pressed in millimeters

or

meters. C entimeters should be avoided. Other units

which may be usedwith SI units are given in Sections

10

and 11.

ASME requirements es tablish th e use of SI units in the following manner-.

either:

As the preferred units with

In

parentheses following quantities

other unitsin parentheses: in other units:

60.0 mm (2.36 in:) 2.45

in

(62.2

mm)

170

kPa (24.7 psi)

25 psi-(172 kPa)

1.60

MJ (1500 Btu)

1500 Btu (1.6 MJ)

.

.600N (61 kgf,)

60 kgf (590 N)

. .

or:

~ . -

As the only unit without customary unit equivalents:

104.5 J

24.5 MN

When nominal sizes that are no t measurements but are names of items are

used, .no conversion should be niade, e.g., -20 UNC thread, 2

X

4 lumber.

Requirements for tabular data are presented in the appendices.

SECTION

8.

CONVERSION AN D ROUN DING

Conversion o f .quantities between systems Qf units requires careful deter.

mination of the number of significant digits to be retained. To convert “one

quart of oil” to “0.946 352

9

liter of oil” is, of course, nonsense because f i e

intended accuracy of the values does not warrant a conversion to seven deci:

mal places. All conversions;‘to be logical, must be rounded based on the pre-

cision of the original quantity, either expressed by a tolerance or implied by

the nature of the quantity.

Where a value represents a maximum or minimum limit that must be

respected, the rounding must be in the direction that does not violate the

original limit. . . . .

The ultimate test of a correct conversion is fidelity to the intended form,

f i t , function, and interchangeability, It is not an automatic process, but re-

quires sound engineering judgment. One or more initial zeroes are-n ot called

. .

10



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‘ A S M E

SI-L 82 0759670 0083958 5 W

. .

“significant”. Zeroes at the end of it number are considered significant only

when they represent the true value more closely than one more or one less.

h

ny conversion take the following steps:

l .

Convert the values and tolerance, if there is one, by multiplying y the

appropriate conversion fa c ta .

2.

Choose the num ber of significant digits t o be retained in the converted

va he . See rounding practices

in

par.

8-.1

and

8.2.

3.

Round off the converted value t o th e desired number of significant

digits using the rules. in the following fable which apply to all the

rounding practices

in

par.

8.1

and 8.2, exmptar.

8.2.1,

~ ~~~~~~

When the First Digit

Dropped Ir:

1 The

Last

Di i t Retained IS:

~

Less

than

5

1

Unchanged

Mare than

5

or S ollowed Increased by 1

by

other than l l zeros

.

5

followed only by zeros Unchangedfven

Increased by 1 if odd:

8.1. Rounding of

General Technical Data

The following chart based on the fust significant digits of t h e conversion

factor and a comparison of the original and converted. values can be used to

determine the number of signifkcant digits- o be retained

in

converted values

other

fian

drawing dimensions and temperatures.

As

an exam ple, conversion of

34

feet t a meters is as follows:

(a) From Appendix

9

the conversion fac tor is

0.3048

m/ft. The converted

value

is 10.3632

m.

(b) The first significant digit of the conversion factor is

“3”

which is

betwee;

1

and

5.

Therefore, the top alf of the charts used.

(c) .Compare the &st significant digi ts of €he original value and the co n-

verted value. The

“1” in 10.3632 m

is lessthan the

“3”

in

34

feet.

. There fore he converted value should be rounded to one more Sig& ì-

cant digit than the original value; thus 34 feet becomes 10.4 meters.

:i

.

.

I

1

1 1



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Ist Significant

Digit of Con -

vanion Factor

1 - 5

6 -9

I s t Significant

Digit of Con -

vertedalue

Round

to Example

st signifi- ame no. signifi- 31 f t X

0,3048

m/ft

cant digit of cant di&s

=

9.4488m which

orig.alue rounds t o

9.4

<

1st signif- . one more signif-

34

t X

0.3048

m/ft

icant digitf icant digit

=

10.3632m which

orig. value. rounds to 10.4

1st signifi- ame no. signif- 25 psi

X

6.895 kPa/

cant digit

of

icant digitssi

= 172.375

Pa

orig.aluehich rounds t o 170

(The final

O

is not a

significant digit bu t

is required t o give

correct magn itude)

> 1st signif- one less ignif- .

10.5

yd

X 0,9144

icant digit of icant digit m/yd

=

9.6102m

orig.aluehich rounds to

9.6

m

8.1.1

R o u n d i n g

o f

Temperatures

Temperatures can be rounded to the nearest whole degree or a multiple

of whole degrees. . .

8 .2 Roun d ing of To le ranced V a lues

There are several methods used to determine the number of significant

digits to be retained in converted.values. 'Following are three common prac-

tices.

8.2.1

R o u n d i n g n w a r d

This practice rounds the converted values to within the range of the origi-

nal dimension and tolerance. For example, 0.880 .t. 0.003 nch is 0.877 o

0.883 inch which equals 22,2758 o 22.4282millimeters. Two.decimal'places

in millimeters could be considered comparable to three decimal places in

inches when considering the accuracy required and the measuring equipment

that would be used

in

machining or inspecting this dimension. The

22.2758

to 22.4282 range would therefore round to 22.28 to 22.42.Note that the

lower limit is rounded up and the upper limit

is

iounded down.



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A b n t

SI-L 8 2 0759670

0083960

3

The advantage of this practice is that absolutely every part ÏÏïëëmg th e

converted dimension and tolerance would also meet the inch dimension and

tolerance. The disadvantage to this practice is tha t folerance is always de-

creased. In .this example the tolerance reduction is 0.0124 mm (0,00049

inch), approximately 8%.

8 .2 .2 R ou nd ing B ased on D ec ima l Places

This practice assumes that the number of decimal places reflects the in-

tended precision. M illimeter dimensions are then rounded to one less place

than the inch dimension and tolerance, but no less than a certain number of

decimal places- enerally tw o dec imal places. h his case

0.880

f

0.003

inch

equals 22.3520 f 0.0762 mm, which would be 22.35 f 0.08 mm. The in-

crease

in

tolerance is

f

0.0038 or a total of 0.0076 mm (0.0003 inch), or

approx. 5%. 0.75 0.01 inch .equals 19.050

f

0.254 mm which would be

19.05 1? 0.25 mm,'a decrease in total tolerance of 0.098 mm (0.00031 inch).

The practice of basing the number of decimal places in the converted value

on the number of decimal places in the original dimension presumes that the

number of decimalplaces in he original dimension reflects the intended

precision. This practice may be most suitable for conversion of millimeters

to inches where the designer is aware that the dimensions are to be con-

verted.

When converting millimeters to inches, inches would be expressed to one

more decimal place than the millimeter dimension. Thus, when expressing

the width of a bracket,

150

mm could be shown and the conversion to 5.9

inches would be satisfactory. However, when s howkg the internal diameter

of a ball bearing, 150.000 mm wouldbe required to get a conversion to

5.9055 inches.

8.2 .3 Rou nd in g Based on Tota l To leranc e

Using another practice, th e number of decimal places is determined by th e

size of the total tolerance applied to the dimension. The following chart may

be used:

Total Toleranœ Converted Value

In Inches In Millimeters

A t

L a

Least Than

Shall be Rounded To

0.000

0 4

0.0004

0.000 4 0.004

0.004 O .O4

O

.O4

-

4

places (0.0001)

3 places

(0.001)

2 places (0.01)

1

place (0.1)

. .

0.880 t0.003 inch equals 22.3520 k 0.0762 mm . The total tolerance is 0.006

inch which is between 0.004 and 0.04 inch.

Thus

the dimension and tolerance

would be rounded to 2 decimal places, 22.35

f

0.08 mm.

13



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‘ ASNE SI-1

8 2

0757670 0083961

5

m

8.3

Numerical Values

in

Formulas

Formulas which use letter symbols to represent physical quantities should

be valid with any units used. However, in practice, fo-rmulas.may havecoeffi-

cients which contain unit conversion fac tors asiwell as empirical or other

factors. Such formulas are tailored for use with specific units, and the engi-

neer may wish to “convert” them

so

that a specific set of SI units can be used

directly. It is essential that any “unit-tailored” formula.be’accompanied by

clear directions for correct units to be used.

8.3.1

escribes a recommended method ofh an dlin g units.

8:3.2

describes

a method of converting formulas which contain coefficients

ór

empiricd fac-

tors which depend on the units used.

8.3.1 If a formula is in unit-independent form , units can be most simply

determined as numerical values are substituted.

Example: The .powerwhich -can be afely transmitted by a rotating,

round shaft is given by

pz”

7D3

W

A .

16-

.

.

in which

T is the allowable shear stress

.

D is the diameter of the shaft

s, the aigular speed of th e shaft

.

. .

For the values

. .

. E -

/

T

=

6000

lbf/in2

= 41.4

MPa

=

41.4

X

lo6

N/m2

= 1.00 n = 0.0254

m

. W = ,1000

ev/min

= 104.7

ad/s

the substitution is carried out as follows:

.

I

n 6000 lbf/in2) 1 ,O0

n j (1000

evlmin)

(2n

rad/rev)

16 ‘(12

in/ft)(33

O00

fGlb f /min HF’

= .

=

18.7

HP

P =

-

41.4X lo6N/m’) (0,0254 )3 (104.7 ad/s)

16

=

13

900

N

m/s

= 13.9 kW

The results agreesince

18.7

HP

0.7457 kW:

~ HP )

=.13.9

W, properly rounded.

A

check of the units should-be made by algebraic “cancelling;’ prior to

carrying out bf the multiplication and/or division.

If the formula is

to

.be used repeatedly to give horsepower in terms

of

diameter in inches and angular speed in rev/min, with a shear stress of

6000

14



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A L f l E SI-L

8 2

O759670

0083962

7

~~ ~ ~~

psi, it m ay be “unit-tailored’’ by incorporating the appropriate conversion

factors with the n/1 6 and 6 000 psi as follows:

~~ ~ ~~~ ~.~~

n (6000 16f/in2) (277 rad/rev)D3

P =

1 6

(12

in/ft) (33 O ft lbf/min

HP

- D3 o

-

53.5 n3 rpm/HP

It is sound practice to write the units of the factor

53.5;

hus when values

such as D

=

1.00

in and 100 0 rpm are substituted,

(1 .O0

in)3

(1000 rpm)

53.5 n 3 r p m / W

= = 18.7 HP

al l units except

HP

ancel properly upon multiplication and-division.

8.3.2

A

formula may have the general

form

A =

K -

B*

C”

where K is a constant which may contain a unit conversion factor as well as

other factors, and

A, B,

and C represenf variables measured

in U.S.

customary

units. If the conversion factors for these variables are a, b , c, then K, (the

corresponding factor for the converted formula) can be obtained

from

Eq.2

Example:

The

power which can be safely transmitted by a rotating, round

shaft is given as

where the following units will be used in theconversion of the formula:

customary

SI

P

H P

kW

D

iir

mm

N

rPmad[s

-



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where p' =

0.7457

kW

HP

d-=-

5.4 mm

in

so that

= 8.12 X 1C6

to prove, calculate

in

bo th systems:

D.= i n

D

=

25.4mm

n.

=

1000 rpm

n = 104.7rad/s

h

ustomary system:.

In

SI:

P = 1 2 X kW/(mm3 rad/s)J (25.4 ml3104.7 rad/s) = 13.9 kW

Proof:

(18.7 HP 0.7457

kW/HP

= 13*9kW

SECTION

9.

DIMENSIONING

There are strict rules about dimensioning but fortunately they are very

l . In general, product engineering drawings are dimensioned

in

millimeters

or decinial parts of a millimeter except for surface roughness which is

expressed in microm eters.

simple.



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A S I E

SI-L 8 2

m

0757670 0083764 O

m

2.

on

drawings where very large. item.Gir6Tëpictëd SÜ as constrúctioon

and, architectural, dimension- n. meters- and decimal parts of a meter

using threeor more decimalplaces, e.g., 32 meters

40-

illimeters

would be321040-m E 3-2.040see rule 3).

3.

If

the drawing. is imensioned “dl n m illimeters or meters,’’. this should

be indicated in n ot e form applicable t o alL references.

4.DÖ ot use centimeters o drawings

5 .

The

size of a. mjllimeter should be kept in mind.

1 min = 1/25.4 n 0:039-370n, about 40-thousandths.

0.1mm-0.004 in

0.01 m-.0.0004

in

Dimensioning

to

more than.

two

decimal places in millimeters will be an

6. Always leave a space between:.the number and symbol:

L71 mm not 1.71mm.

7.

When using fiveor mo re igures in tables and- ex t, space these as

10OQO

or 100 000. Do not use commas. The space should. also b e used with

quantities of four figures when coIum nized-with quantities having five

or more.

8. Dimensional prac tice for drawings is governed by ANSI Y14.5,Dimen-

sioning and-Tolerancing, published b y

ASME.*

9..The use of tables

is

recommended w here conversion of drawings

is

nec-

essary, with dimensions arranged in ascending order of magnitude and

othe r parameters listed in the same manner but in separate columns.

These tables may b e placed on sëparate sheets and may be generated as

computer prin€outs.

uncommon occurrence.

SECTION

IO.

UNITS OUTSIDE THE

INTERNATIONAL SYSTEM

U n i t s U sed w i t h t he I n f e rn a t ion a l S ys tem

Certain units which are not pa rt of

SI

ar e in widespread use. These units

play such an important part that they must be retained for general use with

the InternationaI System of Units. They are given

in

Table 5, I t should be

recognized th at these units need not b e supplemented by th e equivalent SI

units unless desired for clarity.

*See

Appendix 8.

17



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‘ A S M E

SI-& 8 2

0759670

0083965

2

~~~

.

.~

_

~ ~ . .

TA B LE 5 - U N I T S Ü S Ë W I T H THE IN TE R NA T IO N A L S YS TE M

Name

Symbol

Value in SI U n i t

minute

min

1

m i n = 6 0 s

hour h l h = 6 0 m i n = 3 6 0 0 s ’

day

d l d = 2 4 h = 8 6 4 0 0 s

degree

minute

second

liter

L*

1

L =

1dm3

= IO” m3

metric ton

t

1 t = o3 k g =

1 Mg

O

I

1”=

(?r/180) rad

1 ‘

=

(1/60)’

=

(n /lo 800)

rad

1 ”

=

(1/60)’

=

(.rr/648 000) rad

r .

*Liter-This

is

the spelling reeommended by the ASME Metric Study Committee for use

in ASME publication. The alternate spelling, “Litre,’”may be used at the discretion of

the author.

The international symbol

for

lifer is th e lower case “l”, which can easily be

confused with the numeral

“1”.

Accordingly, the symbol

“L”

is recommend-

ed for United States use.

It is likewisenecessary t o recognize, outside the International System,

some other units which are useful in specialized fields of scientific research,

because their values expressed in SI units must be obtained by experiment,

and are therefore not known exactly (Table 6).

TAB LE 6-UNITS USED WITH THE INTERNA TIONA L SYSTEM

IN SPECIALtZED FIELDS2

Name

Symbol

Magnitude

electronvolt

eV

1.602

19-

X 10”’

J

unified a tomic mass unit U

1,660

53.

X

lu ’

kg

astronomical unit ’ AU 149 600

X

IO6m

parsec

PC

30

857 X loî2m

Special Publication 330, p.

14-

National Bureau

o f

Standards. (See Appendix 8.)

SECTION

.11. UNITS ACCEPTED TEMPO RA RILY

In view of existing practice, the CD” (1969) considered it was pre€erable

to keep for the time being, for use with those of the International- System,

the units isted in ‘Fable

3 .



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A S M E SI-L 8 2 W 0757670 0083966 4 W

TAB LE 7-UNITS

TÖ BE

USED

W I T THË

INTERNÄTIÖNÄL-SYSTEM

FOR A LIMITED TIME

Name Symbol Value

in SI

Units

nautical mile

knot

ångstrom

are

hectare

barda)

standard atmosphere

curie(4

röntgedd)

rad@

bar

gal@)

A

a

ha

b

atm

Gal

Ci

R

rad

bar

1 nautical mile

=

€852m

1 nautical mile per hour

=

(1852/3600)m/s

1

A

=0.1

nm

=

1o O

m

l a = l d a m 2 = 1 0 2 m 2

1 ha = 1-hm2

=

lo4 m2

1 b

=

100 fm2

=

lo2 X 10" m2 = m2

1 atm

=

10 1 325 Pa

1 Gal

=

1 cm/s2 = lo-' m/s2

1 R

= 2.58

X lo4

C/kg

1 rad = J/kg

1bar = 0.1 MPa = 10' Pa

1 ci

=

3.7 x 1o'O S

(a) T h e barn is

a

special un it em ployed

in

nuclear physics to express effective cross sections.

(b) The gal is a special unit employed in geodesy and geophysics to express the acceleration

(C) T h e curie

is

a special unit employed in nuclear physics to express activity of radionuclides

(dl The röntgen

is

a special unitem pl oy al to express exposure of

X

or

7

radiations.

(e)

The rad

is

a special unit-employed o express absorbed dose of ionizing radiations. hen

there is risk of confusion with the symbol for radian, rd may be used as symbol for rad.

du e to ravity.

[12th CGPM (1964) Resolution 71.

SECTION

12..

UNITS NOT TO BE USED IN

ASME

DOCUMENTS

12.1

CGS.

Units with SpecialNames. Such units are listed in Table 8, on

nex t page. The CIPM discourages the use of-CGS*units which have special names.

12.2 Other Units Generally Deprecated

As regards units outside the-International System which do not come under

Section

10,

the CIPM considers that t

is

generally preferable t o avoid them , and

t o use instead units of the International System. Some of those units are listed

in Table

9.

*CCS

refers to the centimeter-gram-second system which has been superseded

y

he SI.

I

19



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/ A S I E

S I - l ~

82

0759b70 00839b7

b

I

TKEKEB-CGS~ITS WITH SPECIAL

NAMES”

( N ot

t o be used i n

ASME

publications)

Nameymbolalue

in SI

Units

erg

dyne

poise

stokes

gauss

oersted

maxwell

stilb

phot

erg

P

St

Gs,

G

Oe

Mx

sb

dY n

Ph

1

erg x

J

1

dyn = 10”’ N

1 P

=

1 dyn*s/cm2= 0.1 P a+ s

1

S t

=

1

cm2/s

=

10 ~

2/s

1 Gs Corresponds to

T

1

Oe corresponds to

-

/m

1 Mx corresponds to Wb

1

stilb

= 1

cd/cm2

= lo4

cd/m2

1

ph l o4 lx

1000

?m

3SpecialPublication 330, p. 16, National Bureau of Standards, (See Appendix

8.)

T A B L E 9-OTHER UNITS4

(Mot to be used i n

ASME

publications)

Name

Value

in SI

Units

fermi

1

fermi

1

fm

=

10-l~

m

metric carat 1 metric carat

=

200 mg

=

2 X

lo4

kg

torr 1 torr

=

133.322Pa

kilogram-force (kgf)

1 kgf = 9.806 65

N

calorie (cal)

- 1 cal

=

4.1868J

’

micron

P)

~ p =

p m =

lod

m

X unit

1

X unit . = - I,002X

10-4

mm approximately

stere (st)

I

s t =

I

m3 \

gamma

Y) 1 7 =

1

nT

= T

gamma Y) 1

1

pg = kg

lambda

X)

1

=

11.11

=

1 0 y 6

I

.

4SpecialPublication

330,

p. 17, National Bureau

of

Standards. (See Appendix

8.) ’ .

20



- - ` ,

` ` , ,

` ` , , ,

` , ,

` ` ` , , ,

` ` ` ,

` , , , - ` - ` , ,

` , ,

` ,

` , ,

` - - -

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: A S M E SI-L 8 2

W

O759670 0083968

8

.

SECTION 13.

SI

UNITS

FOR

ASME

USE

TABLE 10-LIST OF

SI

UNITS FOR ASME USE

Other Units

or

Quantity Unit* Symbol Limitations

w e e a n d Tme .

r

planengleadian

solidngle S I

length

m

nautical mile (navigation

...

only)

areaquare ma

volume

...

cubiceter m” . liter (L) for fluids o-dy

(Limit use o L and mL)

(cc shall not beused)

time

angular velocity

velocity

second S

radian-perecondad/s

metererecond/s

minute (min),hour (h), day

Cd),

week, and year

kilometer per hour (km/h)

for vehicle speed, knot for

navigation only

...

Periodic and Related Phenomena

frequency

hertz

Hz (hertz

=

cycle pe r second)

rotational speed

radian per second rad/sev.erecond (r/s)

rev. per minute(r/min

)

Mechanics

mass

density

kilogram kg

kilogramerubicg/m3

meter

. . .

. . .

momentumilogram-metererg.m/s

. . .

moment

of

mom entum kilogram-square meter kg.ma /S

angularomentumilogram-squareeter kg.ml /S

. . .

accelerationetererond

I

momentfnertiailogram-squai.emefer kg.mz

force

newton

moment of fo rce newton-meter Nem . . .

pressurend stress pascal Pa @ascal=newtonerquare

viscositydynamic)ascal-second Pass

viscositykinematic)quareetererz /S

second

per second

per second

squared

. . .

. . .

, . .

(torque) .

meter)

. . .

s . .

second

*Conversion factors between

SI

units and U.S. customary units are given in ASTM

E380.

(ANSI

2210.1). (See also Appendix9.)

21



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i A S M E SI-& 82 E

0 7 5 9 b 7 0

0 0 8 3 9 b 9

T

W

I

~- ~ . ~

TABLE 10-LIST OF St UNITS

FOR

ASME USE (Cont'd)

..

Other Unitsor

Quantitynit Symbol. Limitations

M a n i c s (Cont'd)

surface tension newtonereter N/m.

energy,ork joule J

kilowatt-hour (kWah)

power W . . .

impacttrength . joule

J

. . a

. . .

. .

Hsat

temperature-thermo.**

temperature-other than

thermodynamic**

1in.expansion coeff.

quantity of heat

heat flow rat e

density of heat flow

thermal conductivity

coeff. of heat transfer

heat capacity

specific heat capacity

specific energy

specific enthatpy

specific entro py-

heat rate

rate

kelvin

degree Celsius

meter permeter-

joule

watt.

wa tt per meter squared

watt per meter-kelvin

w at t per meter-

squared-kelvin

joule per kelvin

joule per kilogram-

joule per kilogram

kilojoule per kilogram

kilojoule per kelvin-

kifojoule per kilowatt

kelvin

kelvin

kilogram

degree Celsius ( C)

'kelvin (K)

oc-1

ml(mvK)

. * .

. . .

e . .

W/(m* C)

W/(mz o C)

J P C

J/Org. C)

f . .

. . .

. .

. . .

second

Electricity and Magnetism

electric cu rrent

ampere

electric charge coulom b

vo1.density of charge

coutomb per meter

sur.

density of chargecoulombpermeter

electric field strength

volt per meter

electric potential

volt

capacitance farad

current density

ampere per meter

cubed

squared

squared

mag.fieldtrengthmpereereter Alm

mag.fluxensity tesla- T

magnetic f lux weber

Wb

self-inductanceenry

H

permeabilityenry p e r meter

Hlm

magnetization

ampereereter

A/m

e . .

. . .

*Conversion fact0r.s betweenSI units and V.S. custom ary are given in ASTM

E380.

(ANSI

Z2lO.l).

**Preferred use for temperature nd temperature intervalis degrees

Celsius

CC),

except

for

thermodynamic a i d cryogenic w ork w here kelvins may be more suitable.or tempera-

ture interval, 1 K

= 1°C

exactly.

I

. . .

. .

I . .

. .

..

.

e . .

. .

.

a . .

. , .

C

I

. . .

a . .

22



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, , ,` ` ` ,` , , ,-` -` , ,` , ,` ,` , ,` ---

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' ASME

SI-1

82

m

O759670 0083970

b

TAB LE 10-LIST

OF

S UNITS

FOR

ASME USE (Cont'd)

Othernitsr

'

Quantity Uni t Symbolimitations . .

Electricity and Magnetism (Cont'd)

resistance, impedance

ohm n

conductance siemens

S

resistivity

conductivity

reIuctance

Qhm-metes

n*m

siemensereter/m

ampereereber

R'

. . .

Light

luminous intensityandelad

luminous flux

lumen lm

illumination

lux lx . . .

luminanceandelaerter- . . .

. . .

e . .

squared

*Conversion factors between

SI

units and U.S. ustomary units

are

given in

ASTM E380.

(ANSI

2210.1).

SECTION

14,

INTRODUCING

SI

UNtTS IN ASME PUBLICATIONS

-14.1 It is the policy of ASME that SI units

of

measurement should be in-

cluded in all new papers, publications and revisions ofASME standards.

14.2 Each ASME committee shall have he optionof giving preference

to

.U.$.

customary or SI units.

14.2.1

When preference isgiven to s 1 units,the U S . customary units m ay

be om itted or given in parentheses.

14.2.2

When

U.S.

customary units are given preference, the SI quivalent

shall be given in parentheses, or irl am pplem en tary table as described in Section

15,

14.3 The system of units t o be used in referee decisions shall be stated in a

note in each standard. For example, the n ote should read as follows when.U.S.

customary units are to beused:

Note: The values stated.in

US.

ustomary units are t o be regarded as the

standard.

. *

-

14.4 The calculated SI equivalent for a U.S. customary value shduld be.

rounded to the proper number of significant figures as described herein and in

ANSI 2210.1.

No

attempt should be made to change to .different values which

are used. or may be adopted by other countries, except as covered in 1415 beiow.

14.5 In standards tha t have alternative or optional .procedures based on in-

struments calibrated in either U.S. customary or SI units, converted values need

not be included. If the optional procedures or dimensions produce equally ?c-

ceptable results, the options may be shown similarly to conversions using the

word or rather than parentheses; for example, in a 2-in gage length metal

tension test specimen, the gage length may be shown as " 2 in or SO mm .

23



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--

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I A S M E

SI-1

8 2

m

0 7 5 9 b 7 0 0083973

8

W

L

I

. . ~~ ~

~ ~ ~~ ~~~~~ ~ ~~~

14.6 A specific equivalent, foi example, 25

mm

(1 .O in), need be inserted

only the first time i t occurs inea ch paragraph of a standard.

14.7 Conventions for use of SI and U.S. customary units may differ. The

equivalent expression should always be consistent w ít h th e units used, For e x .

ample, liters per

100

kilometers

YS

milesper gallon (mpg), pitch (which is

the crest-tohcrest distancebetween wo successive threads)vs threads per inch (tpi).

14.8 For methodsof including

SI

equivalents in .tables, seeSection

15.

14.9

On simple illustrations the

SI

equivalen ts may be included n parentheses.

On

more complicated illustrations the dimensions are preferab1y indicated

by

letters and the corresponding SI units and U.S. customary shownin an accompany.

ing table. In the case of charts or graphs, dual scales may be used t o advantage.

14.10 The need for SI equivalents can be avoided for tolerances if they are

expressed in percent. - .

SECTION 15. INTRODUCING SI UNITS

IN

TABLES

15.1

Case

1

Limited TabularMaterial.

Provide

SI

equivalents in tables in

parentheses or in separate columns. Example is givenn A ppendix 1.

15.2

Case 2 One or

i o

Large Tables.

When the size of a table and limita-

tions o f space (on the printed page) make it impractical to expand the table to

include SI equivalents, the table should be duplicated n US. ustomary units and

SI

units. Example is given

in

Appendix

2

If

this procedure results

in

increasing

the size

of

the standard signifcantly it may be desirable to a pp b Case

3.

15.3

Case

3

Extensive TabularMaterial.

Prepare.a summary appendix listing

all of th e units that appear in th e various tables, as shown in Appendix 3; or

consider the use of footnotes, as shown in Appendix

4.

SECTION

16.

METHODS

OF

REPORTING SI EQUIVALENTS FOR -

. EXISTING STANDARDS UND ER EVlSl ON

16.1 For text material n draft preparation, show the SI equivalent

in

the

margin.

16.2 .For tables insert the SI equivalents when there is sufficient space ás

illustrated. Example given. in Appendix 5.

16.3

For tables where space does not permit the

SI

equivalents to be w ritten

in, retype the table.

'16.4 Fof new illustrations it is preferable t o indicate the dimensions with

letters while tabulating bo th inch and 'SI values; Example given in Appendix 6 .

16.5

For

existing illustrations a tabu lation of

SI

eguivalents of customary

units appearing

in

that illustration may be inserted beneath the illustration, Ex-

ample given in A ppe ndix 7.

24



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PL

D IA OF UNTHREADED

PORTION O F SHAFT

SHAL L NOT EXCEED

NOMINAL THREAD DIA

Ex amp le for Case 1

STRAIGHT WHEEL GRINDERS .

. -

H L-ln. (mm)

R

3/8-24 UNF-2A .

1-1/8 (28.6)

1/2-13 UNG2A

1-3/4 (44.4) Governed by

5C8-11 UNG2A

2-118 (54.0)

thickness of

.

5/8-11 UNG2A .

3-1/8 (79.4) wheelsed

3/4-10 UNC-2A

3-1/4 (82.6) . .

. .

Ex amp le fo r Case I - A l t e r n a t e M e t h o d

STRA IGHT WHEEL GR INDERS

H L-ln,

L-mm

R

~~

3/8- UNF-2A

1-1/8 28.6

1/2- 13UNC-BA

1-3/4

a . 4

Governed by

5/8-11

UNC-2A

2-118

54.0

thickness

of

5/8-11

UNCZA 3-1/8 79.4

wheelsed

3/410 UNC-2A 34/4 82.6

25



- - ` ,

` ` , ,

` ` , , ,

` , ,

` ` ` , , ,

` ` ` ,

` , , , - ` - ` , ,

` , ,

` ,

` ,

, ` - - -

8/17/2019 ASME SI-1 -1982.pdf

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Example

for Case 2

A

-

Pin piameter

B

- Inside Diameter of Barrel

D h i d e Width for Sprocket Contact

F -

Chain Height

H -

Barrel Outride Diameter

J

-

Pin Head to Centerline

K -

Pin Head to Centerline

L - Riveted Head to Centerline

P -

Chain Pitch (This is a Theor. Ref, Dimen, Used for

basic cslcu1ations.J

T

- Straight before bend -barre l end

T

-

Straight before bend -p in end

V

- Sidebar end Clearance Radius

-

pin end

V'

- Sidebar end Charance Radius -barre l end

X

- Width of link at Barrel end extending t o a point on the

pitch lineT inches fr om the centerllne as shown,

2 - Width betweenSidebarsat Pin End extending .to a

point on the pitch line

T'

inchesfrom the centerline i r

shQwn

. .

t

i

26



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APPENDIX~Z b n t ' d )

Example

for

Caw 2 (Cont'd)

GENERAL CH A IN DIMENSIONS, PROOF TEST LOAD, STRAND LENGTH,AND

MEASURING LOAD FOR CHECKING GHAIN

LENGTHS

Dimrclt i6ns

in Inches

Chain

No.

H607475

H78

H82

Hl

24

P

2.308 2.609.609.609.075 4.000

A

0.312 0.375.312 0.500 0,562.750

F 0.73.00.75.12.25.56

H 0.75.88.12.88.19.44

_ _ _ _ _ ~ ~ ~ ~ ~~ ~~ ~~~~ ~~ ~ ~

, . . .

~

..

. .

..

Roof test load (lb)

clas M 2 8 0 0 4 O00 . 2 8 0 04 0 00 0 02 0 0 0

class P

3 5 0 0 5 O00 3 5 0 00 0 00000 15 O00

120

h.

strand 52 46 46 46 39 30

120 in.trand .120.02 120.01 120.0120.0119.92 120.00

No. ofpitches

per

nominal

-

Theoreticaliength

of

nominal

Measuring load (lb) . . 190 270 190 430- 54010

. .

. . . .~

Chain NO.

h60

H 7 4 . H75

H78

H02 H124

~~ ~~ ~

P 58.62

66.27

66.27

66.27 78.10

101.60

A

7.92

9.52

7.93

12.70 14.27

19.05

F

18.5

25.1 19.0

28.4

.

31.8

39.6

H

19.0

22,4

18.3

22.4 30.2 36.6

clads

M 12.57.82'58.55.63.4

ass

P

15.62.25.65.64.56.7

3048 mmtrand 52 4666 39 30

3048 mmtrand 3 048.5 3 048.3 3 048.3 3 048.3 3 046.0 3 048.0

Roof test load (kilonewtons)

No.

of

pitches

per

nominal

Theoretical

ebgthofnominal

Measuring load (newtons)

850 1 20050 1 910 24 00 3 600

. , ~

. ~,

27



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I A S M E SI-L 8 2

W

O757670

0083775

5

W

-

~

___.__-

~ - i

APPENDIX 3

Example for Case 3-Listing of All Units Appearing n a Document

- R E L I E F HOLE

D I A FLUID PRESSURES

mm in.

.

kPay psi

. I

3.2

4

. 5.8

- 8

12

14.75

17.5

20.5

23.75

27

9 5

0.126

0,157

.0.228

105

.

15.2

2100.5

4150.2

0.3

12

0.374

0.472

6707.2

1050 .

152

.

210004

0,581

0.689

0.807

0.935

1.063

TOLERANCE

~~ ~

mm.

. .

0.25.010

STRESS

MPa

6.770

10 1 500

20 3 O00

41 5 900

70 102d0

1004

500

205900

41

5

6000

670700

4150

.

,602.

.6900

1000

*Absolute or gage, .as

appropriate. .

in, Hg

kPa 60" F

1.5

O

.44

. . -

. 3

-

.

0.9

-7 ~

. .

2.1

10

3 o

350.4

.. 504.8

kPa

'

lin. HzO

.W0F

0.1

O.4

O

.5 2 o

1

2 "'

4.8

. .

. .

2.5

. .

6.2

5

20



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` ,` , ,` ---

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ASME

SI-1

8 2

m

0757670 0083776 7

~~

~~

~ ~~~

~

APPENDIX 4

E x a m p l e fo r Case

3-Use

of F o o t n o t e s

DIMENSIONS A ND WEIGHTS

OF

WEL DED A ND SEAMLESS STEEL PIPE

Size Identificatio

Plain

Nominal

O.D.

ThicknesseightPI-strong(XS)ched.

(in.)in.)in.) (Ib/ft)** StandardX-strong(XXS) N6.

WalI Endtandard (STD)

0.083 2.47 5L 5LX

5LLX

5LLX

5L 5LX

5LX

2-112 5LX

0.188 5.40

5LX

0.203 5.79

5L 5LXTD 40

0.216 6.13 5LX

.

0.250 7.01LX

5L

.5LX xs 80

0.375 . 10.01

160

5L 5LX xxs

3

0.083

3.03

0.109

3.95

0.125

4.51

0.141

5.06

0.156 ~.

5.57

0.188 6.65

0.216 7.58 -

.

0.250

8.68

0.281

9.66

0.300

10.25

0.438

14.32

0.600 18.58

5L 5LX

5L 5LX

5L 5LX

5LLX

5LLX

5LX

5 L . 5 L x -

5L 5LX STD 40

5LLX

5LLX

5LLX xs 80

160

5LLX xx

3-1/2 [4.000]

0.083

0.109

0.125

0.141

0.156

0.172

0.188

0.226

0.250

0.281

0.318

L

3.47LLX

5.17 5L 5LX ~

5.81 5LX

6.40 5LLX

7.03LX

7.65LLX

9.11L 5LX

-.

10.01 5LLX

11.16 5L 5LX

12.50 s i 5LX

4.53LX

STD

xs

40

80

1 in. = 25.4 nun

**c1 lb/ft = 1.49 kg/m

29



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Classification 10x 20

No. .

I

1 0 x 2 4

Plant Equip ment

Code

1

3415-13

"r

i

L IGHTDUTY CONSTRUCTION-DESIGNED

l 'O USE

A? LEAST

1

HP (1'1 kW)

A T THE WHEEL

Description

I

A-Swingwork

clearance diameter

h)

B-Distance between centers (min)

C-Grinding

wheel diameter and width

(min)

D-Grinding wheel

hole

size

E-Headstock

and

footstock center taper

F-Distance

E

o bottom of machine (recommended)

G-Grinding wheel spindle drive motor

(min)

H-Wheel head swivel

(min)

10

in (254

mm)

20 -

4

in

(508

-

610 mm)

10

X 1 in (25 4 X 25.4 mm)

(See Note

2)

Jamo

1%

HP

(1.1

kW)

90 R

&L

4 2

in (1070 mm)

30



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APPENDIX 6

SPINDLE

FQR

GEARED CHUCK

THREADED CHUCKS

INCH

.. .~

. .. .

N