【Materials】Drill grinding stones are made of premium aluminum oxide, more durable and wear resistance for sharp cutting, sharpening
【Easy to use】All of the grinding stones bits are 1/4'' shank fit electric rotary tools, drill, grinder and pneumatic power tools
【Widely used】 Great for many different grinding applications including debuting inside pipes/surfaces. Filing down stainless steel,grinding striker plate,chamfer the edge of paver stone
【Application】Used for aluminum, stainless steel, copper, jade, glass, metal and non metal grinding, polishing, sharpening
【Package includes】8 pieces 1/4 inch shank various shape rotary grinding stones