The surface processing method of CNC machining workpieces depends primarily on the technical requirements of the surface. However, it should be noted that these technical requirements may not necessarily be those specified in the blueprint, and may sometimes be higher than those in the blueprint due to reasons such as the difficulty to achieve certain technical requirements resulting from different indexing between benchmarks or surfaces with adjacent requirements, and changes in the surface processing requirements resulting from changes in the surface processing method.

After identifying the technical requirements of each surface of the CNC machining workpiece, corresponding processing methods can be selected to ensure that the final surface quality requirements are met, and to determine the number of working steps and processing methods required for each step. The processing method selected should meet the quality requirements of the product, good economic efficiency and high production efficiency. For this reason, when selecting processing methods, the following factors should be considered:

Any CNC machining method has a relatively wide range of processing accuracy and surface roughness that can be achieved, but only within a narrow range is it economical. The processing accuracy of this range is called economic processing accuracy. Therefore, when selecting processing methods, corresponding processing methods that can achieve economic processing accuracy should be selected.

The material properties of the CNC machining workpiece should be considered.

The structural shape and size of the CNC machining workpiece should be considered.

Production rate and economic requirements should be considered. When producing in large quantities, advanced and efficient processes should be adopted. It may even fundamentally change the manufacturing method of the raw material to reduce mechanical processing labor.

The existing equipment situation and technical conditions in the factory or workshop should be considered when selecting processing methods. Processing methods should make full use of existing equipment, tap enterprise potential, and unleash worker creativity. However, continuous improvement of existing processing methods and equipment should also be considered to adopt new technologies and improve process efficiency.