There are many kinds of grinding wheels. According to the abrasives used, it can be divided into ordinary abrasives (corundum and silicon carbide, etc.) grinding wheels and natural abrasive super-hard abrasives and (diamond and cubic boron nitride, etc.) grinding wheels; according to the shape, it can be divided into flat grinding wheels, beveled grinding wheels, cylindrical grinding wheels, Cup-shaped grinding wheels, dish-shaped grinding wheels, etc.; according to the bonding agent can be divided into ceramic CBN grinding wheels, resin cbn grinding wheels, rubber grinding wheels, metal grinding wheels, etc. The characteristic parameters of the grinding wheel mainly include abrasive, particle size, hardness, bonding agent, shape, size and so on. Since the grinding wheel usually works at high speed, it is necessary to carry out a rotation test (to ensure that the grinding wheel will not break at the working speed) and a static balance test (to prevent vibration of the machine tool during work) before use. After working for a period of time, the grinding wheel should be trimmed to restore the grinding performance and the correct geometry.