Broaches are used to machine keyways, splines, and other shapes into a hole in metalworking tasks. They also are used to turn round holes into square, rectangular, or polygonal holes. Keyway broaches are bar-shaped tools with cutting teeth along their length. They are primarily used to create precise keyways in the bore holes of pulleys, gears, washers, and other shaft-mounted components to lock them to keyed shafts. Rotary broaches are cylindrical tools that produce accurate polygonal shapes in holes without requiring additional machining passes. They are commonly used to create sockets on fasteners and other parts. Bushings guide and support keyway broaches during cutting. Shims are used to control depth when creating a keyway with a keyway broach.