Our 3M Stikit Paper Disc Roll 363I discs consist of tough aluminum oxide abrasive particles in a range of grit values bonded with resin on a heavy F-weight paper backing. They are well suited for stock removal and metal finishing, as well as random orbital sanding on both hardwoods and softwoods. The 3M Stikit Paper Disc Roll 363I disc resists wear during aggressive sanding, and its open-coat construction helps prevent clogging to maximize cut and the useful life of the disc.