The traditional machining methods (general machining) are the same as precision and ultra-precision machining methods. With the new technology, new craft, new equipment and the use of new test technology and instruments, the processing accuracy is constantly improving.
The continuous improvement of processing accuracy reflects the processing of materials when the level of material segmentation from the macro into the micro-world development trend. With the advance of time, the original processing accuracy that is difficult to achieve the will become relatively easily touching. Thus, general processing, Precision Machining and ultra-precision machining are only a relative concept, and the boundaries between them are changing over time. Diamond cutting is a typical representative of Precision Turning and ultra-precision machining.