These premium aluminum oxide grain sanding discs are manufactured with the highest standards in the industry and are designed for heavy duty stripping and preparing primed and painted surfaces from metal for finishing, sanding of plastics, fiberglass and composites, light weld blending, preparing and finishing metal, and sanding gel coat and body filler compounds. For use on wood, metal, drywall, fiberglass, or painted surfaces Resin-bonded to resist heat and humidity for longer life Stearate coating helps resist build-up The stick-on adhesive backing holds securely without slipping