The Norton C24-R floor rubbing brick is made of silicon carbide (Crystolon) and has a plain surface for rubbing concrete and removing mold marks, and fit the chucks of most concrete floor grinding equipment. Silicon carbide (Crystolon) is a sharp, aggressive grain that offers high penetration, fast cutting, and high material removal even under light pressure. The C24-R extra-coarse grit size allows for faster cutting than abrasives with a finer grit, and the reusable wooden wedges anchor the brick to the equipment chucks. The brick measures 2 x 2 x 4 inches (H x W x D). (H is height, the vertical distance from lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.) Rubbing bricks (also called abrasive blocks) are rectangular pieces of coarse abrasive material that are used for cleaning and smoothing hard surfaces such as concrete, stone, and other abrasive cutting tools. They can be made of silicon carbide (Crystolon), aluminum oxide (India), or other abrasive materials, and the surface of the brick can be either plain (smooth) or fluted (with diagonal grooves). The bricks can be used in various applications as some handheld rubbing bricks come with a handle, while other rubbing bricks can be used in concrete floor grinders. Norton Abrasives manufactures sanding, grinding, and polishing abrasives, and has been located in the United States since 1885. Norton meets International Organization for Standardization (ISO) 9000 and 14001 standards for quality and environmental management.