A sanding disc is a round piece of abrasive material used in power tools to smooth or shape surfaces. Typically attached to a sander, it comes in various grits, which indicate the coarseness of the material. The lower the grit number, the rougher the disc, making it suitable for heavy material removal, while higher grit numbers are used for finer finishing. These discs can be made from different materials, such as aluminum oxide or silicon carbide, depending on the application. They are commonly used in woodworking, metalworking, and automotive industries to prepare surfaces for painting or finishing.