Nortona?TMs BlueFire F826 AVOS discs with a blend of zirconia alumina and ceramic aluminum oxide AVOS reduce operating heat up to 30 percent over standard aluminum oxide discs, and provide an interrupted cut which pulls debris away from the sanding zone, and allows the operator to see the surface as it is being worked. Coated abrasives have individual abrasive grains spaced at a predetermined distance from one another. This is a closed-coat disc. A closed coat covers 100 percent of the surface with abrasive grains, for more stiffness and better surface finish than an equivalent open coat, where abrasive grit covers 50 to 70 percent of the surface. The fiber backing is more durable, stiffer, harder, and thicker than other backings, for a more aggressive action that is often intended for heavy material removal applications. This disc features a resin bond. Resin bonds have good moisture resistance, are harder and less flexible than glue bonds, and have good heat resistance and grain retention. Resin bonds are useful for abrasive operations with high operating speeds, impact, and sudden loading, as the resin bond is strong.This disc is suitable for use with a die grinder or orbital sander. Use with molded-rubber back up pads on a grinder. Use a hard pad for aggressive cutting, a medium pad for general-purpose applications, or a soft pad for contours and fine finishing work. Or, with a random orbital sander, use a foam back-up pad to match the application. Foam pads come in different combinations of shape and density for finer or more aggressive work. For example, use a low profile for uniform contact with the work surface or a tapered edge for small contours or inside corners, soft density for 320 grit and finer sanding, and medium density for grits coarser than 320. Zirconia alumina and ceramic aluminum oxide combine to produce fast, aggressive cutting. BlueFire is suitable for working stainless steel, superalloys, steel, cast