What is Broaching?

Broaching is a machining process that pushes or pulls a cutting tool (called a broach) over or through the surface being machined. Broaches are referred to as multiple-point linear-travel cutting tools and are used to produce flat, circular, and even extremely intricate profiles, as seen from a section perpendicular to the tool travel. A broach is a series of single-point tools arranged successively in the axial direction along a tool body or holder. Each sequential tooth varies in size and shape in a manner that allows each tooth to cut a chip of the proper thickness.
The shape and spacing of each broach tooth is determined by the length of the part being broached, the amount of material being removed by each tooth, and tonnage restrictions of the broaching machine. The chip space between each tooth is designed to sufficiently accommodate the volume of chips generated.

The concept of broaching as a legitimate machining process can be traced back to the early 1850s. Early broaching applications were cutting keyways in pulleys and gears. After World War 1, broaching contributed to the rifling of gun barrels. Advances in broaching machines and form grinding during the 1920s and 30s enabled tolerances to be tightened and broaching costs to become competitive with other machining processes. Today, almost every conceivable type of form and material can be broached.

Automotive Broaching Machines for the Automotive Industry