Mississippi Welders depressed center fast grinding wheel. It has an aluminum oxide grain with a soft bond for fast shock removal. It is used for ferrous metals (iron, steel, welds, etc.) and low grade stainless steel.Application: metal and stainless steelArbor: 5/8″Diameter: 4″Grit: A24NMaterial: aluminum oxideMax RPM: 13500Series: type 27Thickness: 1/4″