Common coatings include TiN, TiCN, TiAlN, AlTiN, DLC, CrN, diamond coating, etc. Each coating has different characteristics, for example, TiN is suitable for general steel, TiAlN is suitable for high temperature processing, and diamond coating is suitable for non-ferrous metals. The hardness, heat resistance temperature, applicable materials and typical applications of each coating need to be explained in detail.

Also note that users may want to extend tool life, increase cutting speed or process specific materials through coating. Therefore, the answer should include selection suggestions to help users make decisions based on processing needs.