New England Broach Company
199 Long Plain Road
P.O. Box 45
Whately, MA 01093
Tel: (413) 665-7064
  (800) 680-7727
Fax: (413) 665-8457
 
BROACHING MATERIALS:
Material "Broachability" Tool Design
Commonly used grades of regular and free-machining steels. Generally very good. Relatively heavy cuts usually possible. 15º to 20º hook angle depending on hardness. 0.½º to 3º backoff. Use chipbreakers.
Stainless Steels Harder grades tend to dull teeth rapidly, but is generally feasible. Medium cuts should be used. 10 to 20º hook angle 2-5º backoff. Use chipbreakers.
NON-FERROUS METALS
Brass & Bronze Generally quite good. Medium to heavy cuts are best. 0º to 10º hook angle depending on material. 0.½º back off. Use chipbreakers.
Aluminum, Magnesium, Etc. Very good. Quite heavy cuts generally give best results. 15 to 20º hook angle 1 to 3º backoff. Standard tools for steel can be used successfully, but special designs give improved results.
NON-METALICS
  Must be individually evaluated, but good results can often be achieved. Best tool design will depend on characteristics of material.
Cast or Malleable Iron Good-Medium to heavy cuts are best. Cast iron is broached dry. Face angles should be about 6-8 degrees, and back off about the same as for ordinary steel.