Numerical control lathe, turning center, is a kind of high precision, high efficiency of automatic machine tools. Equipped with multi-station dao tower or power tower, the machine will have a wide range of processing technology, performance can be processed straight cylindrical, slash cylinder, circular arc and a variety of thread, groove, worm and other complex artifacts, compensated by linear interpolation, arc interpolation function, and in the mass production of complex parts in good economic effect.

"CNC" is an English Computerized Numerical Control (computer digital Control). Nc machine tool is programmed according to the prior processing program, automatically to be processing parts processing. We put the parts of the processing craft route, process parameters and tool trajectory, displacement, cutting parameters (spindle revolutions, feeding, turning back, etc.) as well as the auxiliary function (in knife, spindle forward, reverse, cutting fluid, etc.), in accordance with the instruction code and procedures prescribed by the CNC machine format write into the processing program list, then this application form on the contents of the records in the control medium (such as punched tape, tape, disk, magnetic bubble memory), and then input to the numerical control machine tool numerical control device, thereby command machine parts.

The medium made from the analysis of the part drawing to control the whole process is called numerical control program. Nc machine tools and common machine tool processing parts of the difference between nc machine tools is according to the program automatically machining parts, while the common machine tool to operate by the people, we just change control machine action program can achieve the purpose of processing different parts. Therefore, nc machine especially suitable for processing complicated shape of small batch and requirement of high precision parts

Because of nc machine tools must, in accordance with the procedures for processing parts, programming good program, input to the numerical control device to direct the work of the machine. The input of the program is by controlling the media.