Nylon Screw threaded hub for easy mounting to the backing pad.Used in a wide variety of applications including cleaning, polishing, blending and deburring.Non-woven synthetic fiber coated with aluminum oxide grain, resists loading for long life without damage to or removal of base material., Coarse (Brown): Excellent for heavy deburring, removing weld spatter and blending tool/mill marks, rust removal.Medium (Maroon): Excellent for light deburring, blending scratch patterns, removing coating/adhesives.Very Fine (Blue): Excellent for cosmetic grain finishing, polishing welds and reducing grinding marks.Backing Pads for Non-Woven Discs are available in Accessories.