3M Radial Bristle Discs are embedded with a long-lasting abrasive material which eliminates the need for messy compounds. Flexible and cool-running bristles are great for hard-to-reach areas or flat surfaces. Clean and remove dirt, rust and oxidation without damaging the underlying surface. Use on platinum, gold, silver, pewter, aluminum, steel and stainless steel. These 3” discs have 3/8” arbor hole and are available in six different grits.