Reamer and It's Types

Reamer:

A reamer is a rotating cutting implement generally of cylindrical shape which is employed to enlarge and finish holes to accurate dimensions to previously formed hole. It is usually equipped with two or more peripheral grooves or flutes which may be parallel to axis (straight reamers) or in a right or left-hand helix (fluted or spiral reamers). It is a multiple edge cutting tool having the cutting edge on its periphery.

Parts of Reamer:

Following are the three main parts of Reamer:

1. Flute

2. Neck

3. Shank

The fluted part consists of chamfer, starting taper, sizing section and back taper length. Chamfer length or bevel lead insures proper and easy entry of the reamer into the hole. The main cutting action of reamer is done by starting taper, the sizing section and to guide the reamers and also smooth or size the hole. The back taper reduces friction between reamers and the whole surface.

Types of Reamers:

Following are the common types of reamers:

1. Hand Reamer

2. Machine Reamer

3. Chucking Reamer

4. Fluting Reamer

5. Expanding Reamer

6. Adjustable Reamer

7. Tapered Reamer

8. Shell Reamer

1. Hand Reamer:

 Hand Reamer

These reamers are operated by hand with a tap wrench fitted on the sequence of the reamer. The work is hold in a vice. The flutes may be straight or helical. Shank is straight with a square tang for the wrench.

2. Machine Reamer:

 Machine Reamer

These are similar to hand reamer, except that the shank is tapered. Machine reamers usually incorporate a chamfer of 45° on the cutting end. These are used in turret lathes and screw machines. These may be classed as fluted or rose type. Fluted reamers cut principally on the chamfer and have radial clearance to very narrow margins of 0.2 to 0.4 mm in width to assure free cutting.

3. Chucking Reamer:

 Chucking Reamer 

These are machine reamers with shorter flutes. These may be either of the type known as rose reamers or fluted reamers. These are using for heavy roughing cuts.

4. Fluting Reamer:

 Fluting Reamer

There the holder are not rigid but are fluting this permits the reamer. To flow the previously made hole naturally and without restrained resulting in a better hole.

5. Expanding Reamer:

 Expanding Reamer

These reamers allow slight increase in their size to allow for wear to remove an extra amount of material. For this the body of the reamers is bored tapered and is slitted. A taper plug runs through the hole end is operated by a screw so that it acts as the expander.

6. Adjustable Reamer:

 Adjustable Reamer

In these reamers separate blades are inserted within the grooves provided within the body of the reamer. The blades are often moved up or down of the reamer.

7. Tapered Reamer:

 Tapered Reamer

These reamers are used to finish the taper holes for cutting the taper things accustomed secure the collars, pulleys etc to the shaft.

8. Shell Reamer:

 Shell Reamer

Solid reamers (upto about 20mm diameter or usually manufactured from HSS) to scale back the value of larger reamers the cutting portion is formed as separate shell which are mounted on standard shanks made of lower cost steel. These reamers are however don't very rigid and accurate inserted tooth or plates in shells in further reduced the value of reamers can tip with cemented carbides.