Norton 38600 80 grit 5" grinding discs are Superior zirconia alumina abrasives makes NorZon® fiber discs outperform and outlast conventional discs. A quick initial cut and self-sharpening action continuously expose sharp, new cutting points. Its cooler-running characteristic results in reduced loading, less frequent disc change-overs, and greater efficiency and productivity. - See more at: http://www.azautobodysupply.com/580nogrdi25.html#sthash.PP4Uq187.dpuf