Recommended Lead Chamfer

Internal Forms: A 45° lead chamfer, going from the major diameter to the minor diameter of form, must be provided for successful internal/ID rotary broaching. 

External Forms: A 45° lead chamfer, going from the minor diameter to the major diameter of form, must be provided for successful external/OD rotary broaching. 

Click here to see the diagram for recommended chamfers for standard broaches.