It is impossible for precision parts processing to complete all the processing content of all surfaces in one process. The entire processing process of precision parts processing can be divided into the following stages:

(1) Rough machining stage. Cutting off most of the machining allowances of each machining surface, and machining a fine benchmark, the main consideration is to increase productivity as much as possible.

(2) The semi-finishing stage. Cut off the defects that may occur after rough machining, prepare for the surface finishing, require a certain machining accuracy, ensure an appropriate finishing allowance, and complete the processing of the secondary surface.

(3) Finishing stage. At this stage, a large cutting speed, a small feed rate and a cutting depth are used to remove the finishing allowance left by the previous process, so that the surface of the part can meet the technical requirements of the pattern.

(4) Finishing processing stage. It is mainly used to reduce the surface roughness value or strengthen the processed surface, and is mainly used for surface processing with high surface roughness requirements (ra≤0.32 μm).

(5) Ultra-precision processing stage. The processing accuracy is 0.1-0.01μm, and the surface roughness value ra is less than or equal to 0.001μm in the processing stage. The main processing methods are: precision cutting, precision mirror grinding, precision grinding and polishing.