6 inch Cloth Backed Zirconia PSA Discs are manufactured using heavy duty y-weight cloth that is covered in premium zirconia grains. These 6" Zirc PSA sanding discs are resin bonded. The resin bond is a strong bonding agent which also contains a grinding aid. The resin bond keeps the zirconia grains on the cloth backing and the grinding aid prevents loading and provides an element of heat resistance to extends the useful life of the disc. The zirconia-alumina abrasive provide a faster cut and longer life than aluminum oxide varieties. Zirconia can outlast aluminum oxide 3-4 times, making them a better option for medium to heavy stock removal especially on metal applications. Additionally, the Y-weight cloth backing is much stronger than a paper alternative and will resist tearing or edge-wear. These 6 inch zirconia cloth backed PSA sanding disk can be used on a wide variety of materials including wood, plastics, all ferrous and non ferrous alloys, but excels on jobs grinding metal. These 6 inch adhesive sanding discs are extremely versatile and can be used for sanding, grinding, deburring, blending, finishing, and polishing applications. Each PSA or pressure-sensitive adhesive disc features a high strength "peel to reveal" adhesive backing. When the paper covering the adhesive is removed the disc should be pressed onto a backing pad or steel disc pad that is attached to a disc sander, random orbital sander, platen disc sander or stationary disc sander. The adhesive used on these PSA Discs are super strong and will not come loose during use. MADE IN USA.