... in some degree. The abrasives made of it are suitable for working on cast iron, non-ferrous metal, rock, leather, rubber, etc ... temperature. 3.Black crystal, hardnessBlack silicon carbide abrasives are suitable for working on cast iron, non-ferrous metal, rock, leather, rubber, etc ... #90#100#120#150#180#220#320#800Black silicon carbide for stone polishing & grinding Black silicon carbide