Metal cutting is to use the rotary motion of the workpiece and the linear or curved motion of the tool to change the shape and size of the blank, and process it into a processing method that meets the requirements of the drawing. Cutting is mostly used for the processing of metal materials. The shape and size of the sub-parts are generally not limited; metal cutting will generate a lot of force and cutting heat; generally based on the tool, the important parameters of the cutting tool include: main angle, edge Inclination angle, rake angle, clearance angle, negative inclination angle, auxiliary clearance angle; the tool material must have certain cutting performance; the metal cutting process is processed by machine tools or hand-held tools, and the main methods include turning, milling, planing, and grinding , Drilling, boring, gear processing, scribing, sawing, filing, scraping, grinding, reaming, tapping, threading, etc.