Broach means to remove material, and broaching is a process that used a toothed tool. Broaching can be divided into two types, and each type has its own purpose. The first one is linear broaching, which is a common process in broaching industry. The broach runs linearly against a surface of the work pieces to control the cut.
The broaching machine is widely used for this process, and this equipment makes the surface broaching in a very simple way. While the workpiece is held by the stationary, the broach will be moved against the stationary. The broaching machine elevator will then lower the broach through the workpiece. Next, the elevator releases the top of the pilot and the puller which totally pulls the broach through the workpiece. After the process, the workpiece will be removed from the machine. The broach here usually moves linearly while rotates to create a gun-barrel rifling occasionally. The other type of broaching is called rotary broaching. In the rotary type, the broach is rotated and pressed into the workpiece to cut an axis symmetric shape. This kind of broaching machine is used in a lathing or screw machine.
Since the broaching is discovered as a very useful way for shape and surface finishing, each broach now can be specialized cut in just one shape. Broaching works best on softer materials, such as brass, bronze, cooper alloys, wood or plastic. But the mild steels and free machining steels are rated as good machinability in the industry.