Flap Discs are made of overlapping coated abrasive flaps and adhering them to backing plate(Plastic backing,fiberglass backing,nylon backing). This special design could provides a cooler running, longer lasti disc. Owing to new layers of abrasive are constantly being exposed, consitent finish is provided during the lifespan of the flap disc. Flap disc are recommended for high stock removal on stainless steel, carbon steel, aluminum, and most alloys.