Brown aluminium oxide is fused and crystallized under high temperature from a mixture of bauxite and other and other raw materials. It is characterized by its high hardness,good toughness and shape in size. Abrasives tools made of it are suitable for grinding metals of high-tensile strength such as: carbon steel,general-purpose alloy steel,annealed malleable iron and hard broze,etc.It also can be used as refractory materials.