For metal materials, the hardness of stainless steel is the largest, followed by cast iron, followed by copper and finally aluminum. The data of precision machining can be divided into two categories: metal data and non-metal data. The processing of ceramics and plastics belongs to the processing of non-metallic materials. In Dalian precision machining, not all materials can be used for precision parts processing. Some materials are too hard and may break the parts if they exceed the hardness of the machined parts. Therefore, these materials are not suitable for precision parts processing, unless they are made of special materials or laser cutting. In the production process, the process of changing the shape, size, position and nature of the production object to make it a finished product or semi-finished product is called the process. It is the main part of the production process. The process can be divided into casting, forging, stamping, welding, machining, assembly and other processes. The mechanical manufacturing process generally refers to the sum of the mechanical processing process of parts and the assembly process of machines. Other processes are called auxiliary processes, such as transportation, storage, power supply, equipment maintenance, etc.