㓉ZE㠓haft diameter: 1/8 inch(3mm); Drill Bit Size: 6mm. 㓐EED㠔he speed is generally 6000-30000 rpm.Too high speed may bend the shaft . ㄅSIGN㍡terial:Tungsten Carbide.The double-line design of the cutter head makes the cutter head more sharp and wear-resistant, with high hardness. 㕓ED㔵ngsten steel grinding head is widely used in industrial sectors such as machinery, aviation, automobile, shipbuilding, chemical engineering and process engraving. ㉎CLUDED㱰pcs Tungsten steel Burrs in a storage box.