CNC machining is a kind of technology, widely used in the machinery industry, it refers to the process of machining parts on CNC machine tools. In numerical control machining, will use numerical control machine tool, numerical control system, etc., numerical control machine tool is a kind of machine tool controlled by the computer, and the instructions of the numerical control system is a set of instructions prepared by the programmer according to the material of the workpiece, processing requirements, the characteristics of the machine tool and the system.

Greatly reduce the number of tooling, parts processing processing complex shape parts do not need complex tooling. If you want to change the shape and size of the parts, only need to modify the parts processing program, suitable for new product development and modification. Stable machining quality, high machining precision, high repetition accuracy, to meet the requirements of aircraft processing. The production efficiency is higher under the condition of multi-variety and small-batch production, which can reduce the time of production preparation, machine tool adjustment and process inspection, and reduce the cutting time due to the use of better cutting quantity. It can process complex surface which is difficult to be processed by conventional methods, and even some parts which cannot be observed. Machine tool equipment is expensive, requiring maintenance personnel to have a high level. In NC programming, the dimensions and positions of all points, lines and surfaces are based on the programming origin. Therefore, Z on the part drawing is better to directly give the coordinate size, or try to quote the size with the same reference.

The shape and inner cavity of parts are of uniform geometric type or size, which can reduce the number of tool changes, and may also apply control procedures or special procedures to shorten the length of the program.