CNC Machining refers to machining with CNC machining tools (CNC Machining). CNC index control machine tools are programmed by CNC machining language, usually G code. CNC machining G code language tells the CNC machine tool to use what kind of Cartesian position coordinates, and control the feed speed and spindle speed of the tool, as well as the tool converter, coolant and other functions. Compared with manual machining, CNC machining has great advantages. For example, the parts produced by CNC machining are very jing, accurate and reproducible. Nc machining can produce parts with complex shapes that cannot be completed by manual machining. Numerical control machining technology has been widely popularized, most machining workshops have numerical control machining ability, the most common CNC machining methods in typical machining workshops are CNC milling, CNC turning and CNC EDM wire cutting (electric spark wire cutting). The tool for NC milling is called a NC milling machine or NC machining center. The lathe that performs the NC turning is called the NC Turning Center. CNC machining G code can be programmed manually, but usually the machine shop with CAM(computer aided manufacturing) software automatically read CAD(computer aided design) files and generate G code program to control CNC machine tools.