... .6, 0.7, 0.8mm 3) Grain: alumina, silicon carbide, zirconia 4) Grit: 16-400Features: 1) Sizes: 100X16mm, 115X22mm, 125X22mm, ... Coated grain: aluminium oxide, silicon carbide, zirconia oxide3) Usage: grinding weld seam, removing burr, sanding floor or furniture, polishing stainless steel fork ... , long life, stable performanceOne hole depressed center aluminum oxide fiber disc for metal sanding disc