The abrasive is a sharp, hard material that grinds the surface of the softer material. Abrasive with natural abrasive and artificial abrasive two categories. According to the hardness of the classification of super-hard abrasive and ordinary two categories of abrasive. A wide range of abrasives, from the softer household detergents, gemstone abrasives to the hardest material of the diamond. Abrasive is an indispensable material for the manufacture of every precision product. Many natural abrasives have been replaced by artificial abrasives. In addition to diamond, the natural abrasive performance is not stable, but still its use value. Diamond is the highest hardness of the abrasive, origin to South Africa, accounting for 95% of the world's total output, the rest of Brazil, Australia, Guyana and Venezuela and other places. Industrial diamond from gray to black range, after grinding can be made of grinding wheel, belt, polishing wheel and grinding powder.