hand reamer?

 Features of Hand Reamers

. the general features of hand reamers

. identify the  types of hand reamers

. distinguish between the uses of straight fluted and helical fluted reamers

General features of hand reamers

Hand reamers are used to ream holes manually using tap wrenches.

These reamers  have a long taper lead. This allows to start the reamer straight and in alignment with the hole being reamed.

Most hand reamers are right hand cutting.

Helical fluted hand reamers have left hand helix. The left hand helix will produce smooth cutting action and finish.

Most reamers, machine or hand, have uneven spacing of teeth. This feature of reamers helps to reduce chattering while reaming.

Types, features and functions

Hand reamers with different features are available for meeting different reaming conditions. The commonly used types.

Parallel hand reamer with parallel shank

A reamer which has virtually parallel cutting edges with taper and  bevel lead. The body of the reamer is integral with a shank. The shank has the nominal diameter of the cutting edges. One end of the shank is squre shaped for tuning it with a tap wrench. Parallel reamers are available with straight and helical flutes.This is the commonly used hand reamer for  reaming holes with parallel sides. Reamers commonly used in workshop produce H8 holes.

Hand reamer with pilot

For this type of reamer,a portion of the body is cylindrically ground to form a pilot at the entering end. The pilot keeps the reamer concentric with the hole being reamed.

Socket reamer with parallel shank

The reamer has tapered cutting edges to suit metric morse tapers. The shank is intergral with the body, and is squre shaped of driving. The flutes are either straight or helical.

The socket reamer is used for reaming internal morse tapered holes.

Taper pin hand reamer

This reamer has tapered cutting edges for reaming taper holes to suit taper pins. A taper pin reamer is made with a taper pin of 1 in 50.These reamers are available with straight or helical flutes.

Use of straight and helical fluted reamers

Straight fluted reamers are useful for general reaming work. Helical fluted reamers are particularly suitable for reaming holes with keyway grooves  or special lines cut into them. The helical flutes will bridge the gap and reduce binding and chattering.

Material of hand reamers

When the reamers are made as a one  piece construction, high speed steel is used. When they are made as two piece construction then the cutting portion is made of high speed steel while the shank portion is made of carbon steel. They are butt-welded together before manufacturing.