Nc (numerical control) machining, it is to point to in the numerical control machine tool parts processing on a process of numerical control machine tool and traditional machining process planning in general is consistent, but also significant changes have taken place. With digital information control parts and tool machining method of displacement. It is to address the changing parts varieties, small batch and complex shape, high precision and automation processing way. Nc machining means, issue instructions by the control system have made cutting tools meet the requirements of various kinds of sports, in the form of Numbers and letters that shape and size of workpiece processing technical requirements and processing requirements. It has come on nc machine tool parts processing process.

Nc machine tool is a kind of using computer to control the machine tool, used to control the machine computer, whether it's a dedicated computer, or general-purpose computer called numerical control system. With auxiliary motion of the nc machine tool movement and is controlled by CNC system of instruction. And CNC system's instruction is by the programmer according to the material of workpiece, the processing requirements, the characteristics of machine tool and the instruction format stipulated in the system (nc language or symbols) compiled. Numerical control system according to the program instructions to the servo device and other features a run or end information to control the movement of the machine tool. When the parts at the end of the process, machine will stop automatically. Any kind of CNC machine tools, if no input in the numerical control system application instructions, numerical control machine can't work. Machine tool control action is roughly including machine start and stop; Spindle start-stop, rotating direction and speed of transformation; Feed movement direction, speed, way; Cutting tool selection, the length and radius compensation; Tool change, cooling fluid of open, closed, etc.