Black corundum with high hardness, toughness, adhesion and hydrophilic, less heat, since the sharp and strong, high efficiency, high quality finish. It is suitable for bicycles, sewing machines, hard metal tools, medical equipment, clocks, glass and stone products, such as grinding and polishing, but also a manufacturing resin cutting wheel, rubber wheel, emery cloth, sandpaper and abrasive pastes, etc abrasive material of choice .