The 3M™ Hookit™ Paper Disc 216U is an aluminum oxide disc constructed on a C-weight, intermediate paper backing. Our 3M™ Hookit™ (hook-and-loop) attachment system makes disc changes fast and easy, meaning the disc can be used again and again for the extent of the abrasive life. Sandpaper discs cut better and last longer when dust isn’t loading the cutting surface of the abrasives. Open coat construction means the abrasive grains are placed with space between them to help evacuate sanding dust and avoid clogging the cutting edge of the grains. The load-resistant coating also allows the disc to continue cutting even when sanding softwoods, paints, and other materials that would, otherwise, clog the disc and hinder sanding ability. Together with the 3M™ Hookit™ backing, these features add up to increased productivity and reduced material consumption. We chose aluminum oxide abrasive, which is a popular choice among industrial professionals because of its fast cut-rate and long life. This mineral makes a tough, durable abrasive that self-fractures to expose fresh cutting edges. Aluminum oxide is suitable for a wide variety of materials in both woodworking and metalworking, including ferrous alloys.