Sadu flap discs for wood, metal and stainless steel, are bonded by a special adhesive on a fiberglass backing. There are 2 types of fiberglass base plates for different industrial areas. The straight type is used particularly on surface grinding due to the straight arrangement of flaps. The conical type is used on curved,lubricious and primed surfaces. Very suitable for edge grinding. All the types are free of iron, sulfur and chlorine (Fe, S, Cl< 0.1 %). There are several kinds of flap discs. Quality depends on density, size, number of flap units.