Our serrated washers, also known as lamellar discs, are plate-shaped sanding discs, in which the abrasive is applied to overlapping slats in a circular shape. They are particularly aggressive in the cut and are therefore ideal for working on surfaces and edge grinding of stainless steel, tough non-ferrous metals, cast iron and steel. Thanks to a relatively long service life and removal performance, you can achieve an even grinding pattern. Blue INOX flap discs have been specially designed to grind or process stainless steel. Brown standard flap discs for all other materials such as metal, wood, plastic etc.