Norton Multisand abrasive sheets have an open coat for longer usage time by resisting loading and durable P-graded aluminum oxide for a more consistent finish. These sheets are used for hand or machine sanding a wide variety of materials, such as metals, wood, plastics, and fiberglass. In coated abrasives, individual abrasive grains are spaced at a predetermined distance from one another. This is an open-coat sheet. An open coat covers 50 to 70 percent of the surface with abrasive grains, for greater flexibility and clog resistance than a closed coat, which covers 100 percent of the surface. An open coat allows for longer usage time because it clogs less, while a closed coat offers a finer surface finish than an equivalent open-coat abrasive. The paper backing is flexible, and offers a more consistent finish than a cloth or fiber backing, while being thicker and more durable than a polyester film backing. Aluminum oxide is a widely used and versatile abrasive material. It is a tough, fracture- and wear-resistant grit that works well with a broad range of materials, from metals to wood. Aluminum oxide is more durable than silicon carbide and often used for material removal and finishing. P-graded abrasive grains are held to a closer tolerance than non-P-graded abrasives, which means that they offer a more consistent surface finish. Abrasives are used for a variety of applications from shaping a part to fine finishing, depending on the grit size. Low grit numbers like 40 are coarse and are used for removing excess material and shaping a part. High grit numbers like 400 are fine and help to create a smooth surface finish. Norton Abrasives manufactures a wide variety of sanding, grinding, and polishing abrasives, and has been located in the United States since 1885. In 1990, Saint-Gobain purchased Norton, keeping its manufacturing facilities and offices in the same location. Norton/Saint-Gobain has been recognized as a Global 100 Sustainable Company, as well as earning ISO 9000 and 14001 certification for quality and environmental management standards.