Technological University of the Philippines

COLLEGE OF INDUSTRIAL TECHNOLOGY

Mechanical Engineering Technology

“CUTTING TOOL DESIGN”

Group 5

Castrojeres, Ariel

Forcadela, Galyrious

Yu, Kenneth

MET – 2C

GROUP 5

CASTROJERES, ARIEL

FORCADELA, GALYRIOUS

YU, KENNETH

MET – 2C

PROF. JERRY LIGAYA

REAMERS

REAMERS

A reamer is a metalworking tool used to create an accurate sized hole. The process is called reaming. They may be used as a hand tool or in a machine tool, such as a milling machine or drill press.

REAMERS MAIN PARTS:-Shank-Body-Angle of Chamfer

Recommended stock allowances for Reaming:

Hole Size Allowances

in. mm in. mm

1/4 6.35 .010 0.25

1/2 12.7 .015 0.38

3/4 19.05 .018 0.45

1 25.4 .020 0.5

1 1/4 31.75 .022 0.55

1 1/2 38.1 .025 0.63

2 50.8 .030 0.76

3 76.2 .045 1.14

Recommended Reaming speeds for high-speed steel Reamers:

Speed

Materials Ft / min m/min

Aluminum 130 - 200 39 - 60

Brass 130 - 180 39 - 55

Bronze 50 - 100 15 - 30

Cast Iron 50 - 80 15 - 24

Machine Steel 50 - 70 15 - 21

Steel Alloys 30 - 40 9 - 12

Stainless Steel 40 - 50 12 - 15

Magnesium 170 - 270 52 - 82

TYPES OF REAMERS:

1. According to Shank:a. Straightb. Taper

2. Ross reamer3. Fluted reamer4. Shell reamer5. Expansion reamer6. Adjustable reamer

According to Shank:

-Straight reamer (precision)A straight reamer is used to make only a minor

enlargement to a hole. The entry end of the reamer will have a slight taper, the length of which will depend on its type. This produces a self centering action as it enters the raw hole. The larger proportion of the length will be of a constant diameter.

-Taper reamer (precision)

A precision tapered reamer is used to make a tapered hole to later receive a tapered pin. A taper pin is a self tightening device due to the shallow angle of the taper. They may be driven into the tapered hole such that removal can only be done with a hammer and punch. They are sized by a number sequence. Such precision joints are used in aircraft assembly and are frequently used to join the two or more wing sections used in a sailplane. These may be re-reamed one or more times during the aircraft's useful life, with an appropriately oversized pin replacing the previous pin.

Ross reamer

A rose reamer has no relief on the periphery and is offset by a back taper to prevent binding. They are primarily used as roughing reamers. The teeth on the end have a 45 degree chamfer that is backed off to produce the cutting edge.

Fluted reamerFluted reamer have more teeth than ross reamer for a

comparable diameter. The lands are relieved for the entire length, and fluted reamer therefore cut along the side as well as at the chamfer on the end. These reamer are considered finishing tools and are used to bring a hole to size.

Shell reamerShell reamers are designed for reaming bearing and

other similar items. They are fluted almost their whole length. Shell reamer heads mounted on a driving arbor. The shank of the driving arbor may be straight or tapered, depending on the size and type of shell reamer used.

Expansion reamerExpansion reamer are similar to adjustable reamers;

however, the amount they can be expanded is limited. The body of this reamer is slotted and tapered, threaded plug is fitted into the end. Turning this plug will allow a 1 inch (25mm) reamer to expand up to .005 in. (0.12 mm). Expansion reamers are not meant to be oversize reamers but to give longer life to finishing reamers.

Adjustable reamerAn adjustable hand reamer can cover a small range of sizes. They are

generally referenced by a letter which equates to a size range. The disposable blades slide along a tapered groove. The act of tightening and loosening the restraining nuts at each end varies the size that may be cut. The absence of any spiral in the flutes restricts them to light usage (minimal material removal per setting) as they have a tendency to chatter. They are also restricted to usage in unbroken holes. If a hole has an axial split along it, such as a split bush or a clamping hole, each straight tooth will in turn drop into the gap causing the other teeth to retract from their cutting position. This also gives rise to chatter marks and defeats the purpose of using the reamer to size a hole.