... corundum - sandblasting abrasive hardness modest, stacking density high, no free silica, more than major, good toughness, Mr Kay brown ... copper material glass, washing jeans precision mould, etc; 2. Free grinding, grinding grade abrasive, applied in tube, optical glass, ... and clocks, glass, crystal glass, jade and other areas of free grinding, is the widely adopted advanced grinding materials; 3. ...