Flap Discs have primarily been designed to replace sanding discs. No backing pads are required with Josco flap discs as they fit directly onto your angle grinder. Due to the cushioning effect of the cloth, a disc one or two grades coarser can be used for maximum rate of stock removal and still achieve a finer finish than what would be obtained with a sanding disc. Grinding marks are less likely to show through paint, epoxy or stove enamel coatings. Flap Discs work best with light pressure, letting the speed of the machine do the work rather than the operator as the laminated flaps stay sharp until the disc is completely worn out.