Pneumatic grinding and polishing tools powered by compressed air. Used for deburring metal parts, weld bead removal, surface finishing, and rust removal operations. Classified by shape including straight type, angle type, and pencil type, supporting grinding wheel diameters from 25mm to 180mm. Suitable for continuous use, lighter weight compared to electric grinders and safe for use in explosion-proof environments. Includes models with rotation speed control and low vibration design. Clearly distinguished from air drills and air sanders by the use of grinding wheels.