Grinding wheels and cut-off wheels are discs or wheels covered in an abrasive grit that are used for grinding, cutting, and machining applications. Grinding wheels cut, grind, sand, or finish metal, glass, wood, brick, or concrete. Cut-off wheels are specifically designed to cut or notch these surfaces. Used with power tools such as grinders and Dremel-style equipment, the wheels' shape and grit material determine their function. Cup grinding wheels can be used to smooth welding seams and prepare surfaces for painting. Diamond and CBN grinding wheels can be used in toolmaking and sharpening applications.