CNC is the abbreviation of computer control machine tool, it is a kind of automatic machine tool controlled by program. The control system is able to logically process the program with control code or other symbolic instructions, and decode it by computer, so that the machine tool performs well specified actions, and the semi-finished products can be processed by cutting tools.

CNC machining has the following advantages:

(1) a large amount of reduction in the number of the tooling, and the complex parts of the parts do not require complex tooling. If we want to change the shape and size of the parts, it is only necessary to modify the processing program for the parts, and it is suitable for the development and modification of the new products.

(2)The processing quality is stable and the processing precision is high.

(3) The production efficiency is high under the condition of multi variety and small batch production, it can reduce the time of production preparation, machine adjustment and process inspection, and the cutting time is reduced by using the best cutting volume.

(4) it is possible to process complex surfaces that are difficult to be machined by conventional methods, and can even process some unobservable parts.