This 7-piece set of extra-long tungsten carbide burr files is designed for use with electric drills, routers, or die grinder tools with a 1/4" shaft. Ideal for polishing, grinding, shaping, and burnishing wooden surfaces, these burrs feature a double diamond cut for increased strength compared to cheaper alternatives. Made from tungsten carbide, not HSS, they are built for durability. The extra-long design (175mm total length) provides access to restricted and awkward areas. Each burr has a 6mm / 1/4" shank. These burrs are suitable for grinding most steel types, glass, plastics, marble, granite, and various other materials. The set includes a Cone burr, Small, Medium, and Large Cylindrical burrs, a Rounded Cylindrical burr, and Small and Large Flat-Tipped Cylindrical burrs. Supplied in a box for convenient storage and transportation, this is a professional quality carbide burr set suitable for everyday or commercial use.