broaching machine  broaching machine,  tool for finishing
surfaces by drawing or pushing a cutter called a broach entirely
over and past the surface. A broach has a series of cutting
teeth arranged in a row or rows, graduated in height from the
teeth that cut first to those that cut last. Since the total
depth of cut is distributed over all the teeth, each tooth
removes only a few thousandths of an inch. Broaching is
particularly suitable for internal surfaces such as holes and
internal gears, but it can also shape external gears and flat
surfaces. Broaching machines are usually hydraulically operated.