If you are looking for flap discs, consider these points, and you’ll be able to choose the right disc. Flap Wheel Shape Flap discs are used mainly on the right angled grinders, and they are designed with hubs that allow work to be done on the face. Their angle provides a greater surface contact for stock removal on a flat surface. Flat flap discs are used on the flat surfaces, and they are the best choices for blending and smooth finishing and airfoil polishing . Plate Material The second thing that demands your attention is the backing plate you may use. All flap discs are a combination of abrasive flaps that are adhered to a rigid backing plate. Aluminum backing plates are the least popular. Read more