Rolling bearing materials include rolling bearing parts materials and cages, rivets and other auxiliary materials. Rolling bearings and their parts are mostly made of steel, and the steel used for rolling bearings is usually high carbon chromium steel and carburized steel. With the development of modern science and technology and the increasing use of rolling NTN bearings, more and more high requirements for NTN bearings, such as high precision, long life and high reliability. For some special purpose NTN bearings, NTN bearing materials are also required to have high temperature resistance, corrosion resistance, non-magnetic, ultra-low temperature, radiation resistance and other properties. In addition, NTN bearing materials also include alloy materials, non-ferrous metals and non-metallic materials. In addition, NTN bearings made of ceramic materials are now used in locomotive, automobile, subway, aviation, aerospace, chemical and other fields.