Methods of Broaching

Broaching methods can be classified as

1. Internal or Hole Broaching:

In this, normally the work remains stationary and the broach is either pushed or pulled through the same to produce a hole of desired shape and size.

2. External or Surface Broaching:

In this either the work or the broach is moved past the other to produce a groove or surface of desired shape and size on the external surface of the work.

3. Pull Broaching:

Mostly adopted for internal broaching. In this, the work remains stationary and the broach is pulled through the same to produce the hole of desired shape and size.

4. Push Broaching:

Adopted mostly for internal broaching of relatively lighter jobs. The work piece remains stationary and the broach is pushed through the same. However, it can be used for external broaching also.

5. Continuous Broaching:

It is a method suitable and largely adopted for broaching of identical components on large scale. In this method, the broach remains stationary, while the work pieces move continuously past the same along a horizontal or circular path.

Broaching Speeds:

Broaching operation uses lower cutting speeds. Selection of proper speed for broaching a particular component will be decided by the following factors:

1. Hardness of work piece material.

2. Length of broaching.

3. Type of material to be broached.

4. Rigidity of the component to be broached.

5. Economic considerations for the operation.

Broaching speeds for some common materials are

Carbon Steel --- 3 to 8m/min

Cast Iron --- 6 to 30 m/min

Copper Alloys --- 8 to 10 m/min

Free Machining Steel --- 10 to 12 m/min