Dalian NC machining is mainly used to process various planes (such as horizontal plane, vertical plane and inclined plane and various grooves, such as T-shaped groove, swallow tail groove, V-shaped groove) and linear forming surface. If equipped with profiling device, it can also process space surface, such as turbine impeller, spiral groove, etc. The tool structure of this kind of machine tool is simple and does not cut when returning, so its productivity is low. It is generally used in small batch production of single piece. 

As CNC technology is a typical and widely used integrated technology of mechatronics and optics, China urgently needs a large number of technical personnel at all levels from research and development to use and maintenance. Due to the narrow division of professional courses in school education, it is still difficult to meet the requirements of some enterprises for integrated processing and maintenance talents. 

Dimensional requirements, such as the diameter of the cylinder, there are strict requirements, positive and negative errors are qualified parts within the prescribed requirements, otherwise they are all unqualified parts; length, width and height also have specific strict requirements, positive and negative errors are also prescribed, such as an embedded cylinder (take simple basic parts for example). If the diameter is too large, beyond the allowable range of error, it will cause the situation of insertion. If the actual diameter is too small, beyond the lower limit of the allowable negative error, it will cause the insertion to be too loose and unstable.