The usage of grinding wheels is very large. There are parallel, bevel, cylindrical disc-shaped or wheel-shaped grinding tools, which are made of abrasives and binders such as ceramics, resin and rubber. It can grind and cut the surface of the material to be processed by high-speed rotation. Brown corundum sand is the main material for making grinding wheels. The grinding wheels made of it not only have high hardness, but also have better grinding force than those made of other materials.