Norton Gemini 57A24-R Type 16 Cones, 2-3/4 in. x 3-1/2 in. x 5/8-11 in. 

Norton Gemini Cones are manufactured with 57A aluminum oxide abrasives and are for steel, steel alloys and irons. Norton Cone applications include hard-to-reach areas inside castings, removing flaws and cracks, and removing metal corners.