A flap wheel is comprised of a number of strips of abrasive material bound together into a wheel. Ours are "potted" wheels, bound together in a mold with epoxy resin to form a uniform, smooth and continuous running wheel. Flap wheels are generally made of X-weight, aluminum oxide resin bond cloth, although they may be made in other materials on request. The smaller flap wheels (3" diameter and smaller) are mounted on a plain or threaded shank.Mounted flap wheels are excellent for use in small, narrow curves, tubes, cavities, recesses and concave and convex areas. The larger wheels are often used for stock removal and shaping. While flap wheels can be ordered to any of the specifications shown below, they may not be available in the sizes you specify. If so we will contact you in an effort to find a size, grit and material combination to suit your needs. In addition we reserve the right to cancel orders (and credit your account) for small quantities of uncommon specifications, regardless of normal minimum quantity requirements shown