Parts turning is an economical and effective machining method for outer surface, but in terms of its economic accuracy, it is generally suitable for rough machining and semi-finishing machining of outer surface. Grinding is the main finishing method of outer surface, especially suitable for all kinds of high hardness and quenched parts finishing; Finishing is an ultra-precision machining method (such as rolling, polishing, grinding, etc.) after finishing, which is suitable for parts with high precision and surface quality requirements.

Ordinary turning: Suitable for cylindrical processing of shaft parts in various batches, widely used. Small batch of single pieces often use bedroom lathe to complete the turning processing; Medium batch, mass production is using automatic, semi-automatic lathe and special lathe to complete the turning processing.

Nc turning: Suitable for small and medium batch production. In recent years, it is more and more widely used. Its main advantages are good flexibility, short time for equipment adjustment and preparation when replacing machining parts. With less auxiliary time in machining, efficiency can be improved by optimizing cutting parameters and adaptive control. Good processing quality, less special fixture, the corresponding production preparation cost is low; Machine tool operation technology requirements are low, not affected by the operator's skills, visual, mental, physical and other factors.