国产福利资源网在线观看丨在线免费观看国产黄色大片丨亚洲国产精品嫩草影院在线观看丨国产精品黄色福利电影大片丨国产日韩欧美三级丨欧美特黄三级成人大片丨免费三级网站丨直接在线观看的三级网址 Precision machining is a process of changing the overall dimension or performance of the workpiece with machining machinery. According to the temperature state of the workpiece to be processed, it is divided into cold processing and hot processing. Generally, it is processed at normal temperature without causing chemical or phase changes of the workpiece, which is called cold processing. The process of using datum in the processing and assembly of precision machined parts is called datum process. The benchmarking process is divided into different, according to the use of assembly datum, measurement datum and position datum. Machining process flow is the step of workpiece or part manufacturing and processing. The process of directly changing the shape, size and surface quality of blank by machining is called machining process flow. For example, the processing process of an ordinary part is rough machining - finish machining - assembly - Inspection - packaging, which is a general process.