... , 2.melting point 24500c, 3.density 2.51g/cm3 Boron Carbide, a black powder, is the hardest of the conventional abrasives ... to grind and polish hard metal alloy, super-hard metal, high carbide steel, jewel, hard ceramic and other hard materials, to manufacture ... matal boride, metal ceramic, boron steel, boron alloy and for special welding and refractory materials.Packing 50kgs packed in iron drum ...