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
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.
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.
  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.