For the processing of the tenon of the special tool for a lot of style, there are hollow chisel, with a drill bit hollow square chisel, chain hit the knife and machine chisels and so on. The hollow side of the chisel has a crescent-shaped edge that cuts the corners around the borehole. The hollow square with drill bit is the combination of drill bit and square chisel, and the drill bit is installed in the hollow square chisel. Chain-type knife is a continuous rotation of the chain-type multi-tooth tool, which is similar to the processing of the end of the milling or longitudinal sawing. When the machine is opened with a chisel, the chisel is used for the cutting movement.