Details of Chasers

Details of Chasers

Details of Chasers -

Tangent chasers are flat type blades threaded on one side and mounted in holders so that this side, at its inner end, contacts the work tangentially to form the cutting edge. These chasers are resharpened on the end only. The chamfer remains constant throughout the life of the chaser.

There are two types of tangent chasers: one has the helix angle incorporated in the chaser, the other has straight threads ground in its face and the proper helix angle is obtained by tipping the chaser in the die head. The type used depends upon the make of die head.

Tangent Chaser

Circular chasers have a single flute which provides the cutting edge and also the necessary chip space. These chasers are mounted on holders and resharpened on the cutting face only. The chamfer remains constant throughout the life of the chaser.

Circular Chaser

Inserted radial chasers are thin blade type chasers that are locked in the die head carrier or holders. They are especially advantageous for heat treated stock or when chasers tend to dull rapidly, since dull chasers can be replaced with sharp chasers in a few minutes. The inserts can be discarded when dull or they may be resharpened on the chamfer. Occasionally they are lightly reground on the cutting face.

Inserted Type Radial Chasers

Milled type radial chasers fit into chaser slots machined in the body of the chaser head. Chasers of this description have the threaded end formed with a positive rake angle. They are furnished with either cut or ground threads and are usually resharpened on the chamfer. Occasionally they are lightly reground on the cutting face. The helix angle is incorporated in the chaser.

Milled Type Radial Chaser

Hobbed type radial chasers have the threaded and formed concave as produced by a hub or tap. General practice is to sharpen these on the cutting face. Occasionally they are lightly ground on the chamfer. The helix angle is incorporated in the chaser.

Hobbed Radial Chaser