Rotary Broaching Defined

For people like me without a background in metalworking, it is often hard to find the meaning of industry terms that most of you don’t think twice about. For instance, the term “rotary broaching” is one that I often see, but didn’t know the meaning of. If I wasn’t dealing with the metalworking industry, I would hav

For people like me without a background in metalworking, it is often hard to find the meaning of industry terms that most of you don’t think twice about. For instance, the term “rotary broaching” is one that I often see, but didn’t know the meaning of. If I wasn’t dealing with the metalworking industry, I would have to guess that a rotary broach is a decorative piece of jewelry that spins. Knowing this obviously isn’t the case, I finally took the time to investigate the meaning.

Rotary broaching, also known as wobble broaching, is when internal and external polygonal profiles are single-point shaped rather than form punched. On a live tooling station, the part rotates synchronously with the tool while the holder is held in an endworking position. The broach holder is set at an angle to the centerline of the part. It revolves eccentrically in the spindle, cutting the periphery of the part in either the ID or OD. Not bad for a beginner, don’t you think?

I found this definition while reviewing a past article published in PM on our Web site. If you are looking for information on rotary broaching as well, I encourage you to visit “Rotary Broaching 101” or “Broaching On A Lathe” on PM’s Web site.

In this column space every month, I plan to define a metalworking term that I have recently learned about. If you have an idea for something that I can write about or a term you would like to teach me, please e-mail me at lbeckman@productionmachining.com. I appreciate your help and support, and I look forward to hearing and learning from you—the experts in the field.