Boron Carbide, black powder, is the hardest of the conventional abrasives. Its Mohs hardness is 9.36, melting point 2350℃, density 2.51g/cm3. 

It has following unique features: neutron absorbing, of semi-conductivity, low thermal conductivity, high grinding efficiency and no reaction with either acids or alkali etc. 

Boron carbide steel, jewel, hard ceramic and other hard materials, and to manufacture wear-resisting parts, metal cutting tools, nozzles and neutron-absorbing rods,used as metal additive for compound materials for military planes and as raw materials for metal boride, metal ceramic,boron steel, boron alloy and for special welding and refractory materials.