Black aluminium oxide(lower aluminium oxide abrasive)is a new type abrasive material for polishing various metal.Black aluminium oxide abrasive is featured with high hardness, strong tenacity, good self-sharpening, better cohesisness, higher durability, less heat generated in grinding and giving the metal works high finish, less power weakened in grinding.It is mostly used in grindin and polishing stainless steel, metal works , optical glass, bamboo or articles.And it is also the new grinding material of producing colophony grinding wheels, slice, and emery cloth.