Before processing precision mechanical parts, we must pay attention to the density of the material. If the density is too high, the hardness is also very large. If the hardness exceeds the hardness of the lathe tool, it can not be processed. It will not only damage the parts, but also cause danger, such as the tool flying out and injuring people. Then, what are the requirements of material for precision machine parts processing? For precision machined materials, there are two main categories: metal materials and non-metal materials. For metal materials, the hardness of stainless steel is larger, followed by cast iron, followed by copper, and finally aluminum. The processing of ceramics and plastics belongs to the processing of non-metallic materials. Stainless steel materials used in precision mechanical parts processing 1. First of all, the requirements of material hardness. For some occasions, the higher the hardness of the material, the better. It is only limited to the hardness requirements of the machined parts. The machined materials can not be too hard. If they are harder than the machined parts, they can not be machined. 2. Secondly, the material is moderate in hardness and softness, at least one grade lower than the hardness of the machine parts. At the same time, it depends on what the function of the processed devices is and the reasonable selection of the machine parts. In a word, there are still some requirements for material quality in precision machining, not all materials are suitable for processing, such as soft or hard materials, the former is not necessary for processing, and the latter is unable to process. Therefore, generally speaking, for mechanical processing, the material quality is lower than the hardness of the machine tool, so that it can be processed. Not all materials can be processed precisely. Some materials are too hard to exceed the hardness of the machined parts. They may break down the machined parts. Therefore, these materials are not suitable for precision machining unless they are made of special materials or laser cutting.