Cleans without harming the basic material.The discs themselves contain no metals, so there is no danger of corrosion. The coarse non-woven material will not glaze or load up, even by heavy contamination like cleaning paint off metal. The ideal cleaning disc for cleaning welds, removing rust, descaling and removing paint from the surface of metallic objetcs and for decorative surface finishes on stainless steel and aluminium. 11500 RPM max. operating speed.