Dremel 953 Aluminium Oxide Grinding StoneDremel 950 aluminum oxide grinding stone. A high-quality industrial abrasive made for extended general-purpose grinding on metals, castings, welded joints, rivets and rust. Two stones includes.-Ideal for sharpening, deburring and general purpose grinding on most materials including stainless steel-Specially designed for working with conic surfaces-Use the 415 dressing stone to clean the surface of the grinding stone-Two 953 grinding stones per package(User Tips)-Use the 415 dressing stone to clean the surface of the grinding stone and restore its original shape. You can also use the dressing stone to create a grinding stone with just the right shape for that special job.-For best results, insert the accessory bit all the way into the tool and then back it out slightly before tightening down. This provides plenty of shank for the collet or chuck to hold onto the bit.