Arc Abrasives 714051803-3 Zirconia Alumina Airfield Belts are 1/2-inch wide x 18 Inch long. Zirconia Alumina is an excellent general purpose abrasive, ideal for use on steel, aluminum and composites. These belts have a closed coating on an X-weight backing made from 65% polyester and 35% cotton with a phenolic resin bonding. For dry grinding only. 40 Grit. Pack of 50 belts.