The Weldmark by Norton® 4.5 inch diameter, type 27, flat abrasive flap disc is best when used for applications like beveling, blending, deburring, and stock removal of 300 and 400 series stainless steel, cast iron, soft carbon steel, super alloys, and titanium. Constructed with a cloth backed, high density zirconia coated 40 grit, coarse grade surface, for a rough finish. Has a 5/8-11 inch threaded hub, used with a right angle grinder, and max rated for 13300 RPM. Meets or exceeds ANSI safety standards.