... , have many foreign customers 2.specialize in producing knife sharpening wheel 1.knife sharpening wheel be written according to the order, shape ... Hard alloy, Optical glass, vitrify and other hard friable materials.Black silicon carbideCblack Harder than corundum, crisper, less flexibility.Suitable for ... process weak Tensile strength metallic and Nonmetallic material, i.e. knife sharpening wheel