In occasions requiring low friction coefficient without high hardness, such as stamping die, which is a die for stamping non-ferrous metals, such as copper, aluminum, etc., cool r chromium nitride (CRN) coating is an ideal choice. Cool r coating is more tough and durable than other coatings in friction and wear occasions. Compared with cool n coating, it has stronger corrosion resistance to water solution. Cool r coating has high surface hardness, low friction coefficient and low residual stress, which makes it suitable for wear resistance and metal to metal friction. Moreover, chromium nitride coating has high toughness, corrosivity and chemical resistance to water solution, and can obtain ultra thick PVD coating with coating thickness of more than 10um, and has certain lubricity.