... steel, High-carbon steel,Chromium corundumPAPink,rose-red Sharp cutting, good edges holdout, durableSuitable for form grinding, knives, ... carbideSuitable for grinding Hard alloy, Optical glass, vitrify and other hard friable materials.Black silicon carbideCblack Harder ... flexibility.Suitable for process weak Tensile strength metallic and Nonmetallic material, i.e. single alundum abrasive cutting tool