Bit made from high quality base materials of consistent hardness. Various shapes for widest possible range of applications. Use on especially hard materials such as cast iron, unhardened steels, non-ferrous metals, hard metal alloys, welded joints, rivets and rust. Ideal for sharpening, deburring and general purpose grinding. Accurately dimensioned shanks 3/32" (2.35mm) or 7/64" (3.0 mm) for highest concentricity.