With their highly flexible and conformable bristles, these 3M discs can be used for a wide variety of cleaning and finishing needs. They can get into small grooves and fine details with ease and can be used on most metals. Since the abrasive is integrated into the bristles, no compounds or chemicals are needed. 3M discs are mounted in screw-top mandrels singly or in multiples. Max speed is 30,000 RPM. Ideal for semi-finishing and pre-polishing purposes. Use 3-6 discs per mandrel for best performance. Produces a uniform finish that is easily controllable. Great conformability and flexibility - easily finishes detailed or hard to reach areas. Runs clean - therefore no chemicals or compounds are required. Runs cool - safe for delicate pieces.