... the drill bit, the cutting depth includes: 30mm , 55mm , 75mm , 110mm. 2)Material:M35 M42 M2 9341. We can supply drill bitnormal annular ... , M2,M35,M423)Diameter: from12mm to 100mm4)Use: widely used in machinery manufacturing, railways, bridges, ship building, airplane manufacturing and gas ... of drilling is much better and quicker than the common drill bits. drill bit