The United Abrasives/SAIT Aluminum Oxide Individual PSA Cloth Discs are specially developed with X-weight Egyptian cotton cloth backing making it ideal for ferrous and/or non-ferrous metals like iron, steel, aluminum, copper, stainless steel and high tensile steel. The disc has a closed coat structure. The discs hot melt adhesive back permits for quick change and less downtime. It also features strong resin over resin bond construction that is resistant to heat and moisture. The disc is sold as 50 per pack.