Not what materials can be precision mechanical parts processing, some materials are too hard more than the hardness of the processing machine parts, it is possible to crash the machine parts, so these materials are not suitable for precision machining, unless it is a special material made of machine parts or laser cutting.

For precision machining of materials are divided into two categories, metal materials and non-metallic materials. For metal materials, the hardness of stainless steel is the largest, followed by cast iron, followed by copper, and finally aluminium. Non-metallic materials such as ceramics, plastics.
1, first of all, the requirements of the hardness of the material, for some occasions, the higher the hardness of the material is the better, but is limited to the hardness requirements of the processing machine, the processing of the material can not be too hard, if harder than the machine is unable to process.

2, secondly, the material soft and hard moderate, at least one grade lower than the hardness of the machine, but also to see what the role of the processed device is to do with a reasonable selection of materials for machine parts.

In short, precision machining of the material requirements or some, not what material is suitable for processing, such as too soft or too hard material, too soft without the need to process too hard material is not processed.

Therefore, before processing must pay attention to the density of the material, if the density is too large, equivalent to the hardness is also very large, and if the hardness exceeds the hardness of the machine (lathe turning tool), it is impossible to process, not only will damage the parts, but also cause danger, such as turning tool flying out to hurt people. Therefore, generally speaking, for precision mechanical parts processing, the material material should be lower than the hardness of the machine tool, so that it can be processed.