Resin Fibre Sanding Disc, aluminum oxide, 50 grit x 7" (177.8 mm) with 7/8" (22.23 mm) arbor, 8,500 Max RPM, 3-pack. Excellent quality aluminum oxide steel Resin Fibre Sanding Disc. Ideal for weld grinding, blending, finishing, deburring and other general purpose applications. Can be used on most types of steel as well as fiberglass and plastics. Constructed with a heavy vulcanized fibre back, coated with abrasive grains, and bonded together with a tough, heat resistant resin for fast cutting action and long life. For use on Right Angle Grinders. ISO 9001 certified.