1. Roughing stage. Roughing is the removal of most of the machining allowance on each surface, so that the rough shape and size close to the finished product. The stage is characterized by the use of high-power machine tools, the choice of a larger amount of cutting, as much as possible to improve productivity and reduce tool wear.

2. Semi-finishing stage. Semi-finishing is the completion of the secondary surface of the machining, and preparation for the main surface finishing.

3. Precision Finishing stage. Precision Finishing is to ensure that the main surface of the drawings to meet the machining requirements.

4. Final Finishing stage. Final Finishing is the surface roughness and high precision machining of the surface. This stage cannot generally be used to improve the position accuracy of the part.

However, the division of the machining stage is based on the whole process of the part machining, and cannot be judged by the machining of a certain surface or the nature of a certain process. At the same time in the specific application, it cannot be absolute, for some heavy parts or margin of small, low precision parts, you can finish the surface after a rough finishing.

BY NICOLE