The Weldmark by NortonĀ® 4.5 inch diameter, type 27, flat abrasive flap disc is best when used for applications like beveling, blending, deburring, and stock removal of 305 and 400 series stainless steel, cast iron, soft carbon steel, super alloys, and titanium. Constructed with a cloth backed, high density zirconia coated 80 grit, medium grade surface, for a smooth finish. For use with a 5/8 inch threaded hub and right angle grinder, and max rated for 13300 RPM. Meets or exceeds ANSI safety standards.