... 25mmC/CFine/Coarse50pcs/ctn Material:Brown Aluminum Oxide (gray colour,code:A ), Brown Aluminum Oxide (white colour,code:WA) Black Silicon ... ), Green Silicon Carbide(green colour,code:GC ) Specifications: Use Aluminum Oxide stone for harder steels. Use Silicon Carbide stone for working ... on softer metals, such as brass,iron or stainless steel. They also can be supplied in ...