The PFERD POLIFAN-CURVE flap disc is designed for precise grinding of fillet welds, with a large-radius profile suited to the weld geometry. Its 40-grit zirconia abrasive delivers a high stock removal rate and excellent service life on stainless steel (INOX) and steel. The 4-1/2-inch disc has a 7/8-inch arbor for use with an angle grinder.