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