These 4-1/2" x 1/4" x 7/8" depressed center grinding wheels from Mercer Abrasives are manufactured for "Today's Angle Grinder". They grind metal effortlessly and have a long life and fast stock removal for increased productivity. The A24U style offers a hard-bond, longer life and aggressive stock removal, and the single grit wheels give consistent performance at any angle. Used to grind ferrous metals, steel, structural steel, rebar, iron pipe, bar stock, and metal tubing.