... : 6mm, 6. 35mm(1/4"). Used for shaping, smoothing & removal hardened steel. Carbide rotary burr 8pcs set,carbide rotary fileShank Diameter: 6mm, 6 ... upon request.Used for shaping, smoothing & removal hardened steel, stainless steel, fired ceramics, plastics, hardwoods and so on. Tungsten carbide burr set 8pcs ...