..This high quality Rotary burr set is for use with an electric drill to grind, polish, shape and burnish wood surfaces. They come on a 6mm Shank and can be used for all types of deburring, grinding, cleaning, sharpening and various other uses, they will grind most steel types and glass, plastics, marble/granite and various other materials. Most Burr's range from 54mm - 68mm in length while the diameter is 12mm at their widest. This set is perfect for the home DIY enthusiast where detail is important or finishing requires delicate work. For use with 1/4" inch die grinders, routers and drills. Specifications • Double Diamond Cut • 6mm shank • Carbide tipped • Professional quality Included • Cylindrical Burr • Rounded Cylindrical Burr • Extra Rounded Cylindrical Burr • Spherical Burr • Flat tipped cylindrical burr