We can supply normal annular cutters(annular hole cutter)and special drills Detail description about our annular cutters 1)Max.drilling depth:30mm/55mm/75mm/110mm 2)Material:HSS9341, M2,M35,M42 3)Diameter: from12mm to 100mm 4)Use: widely used in machinery manufacturing,railways, bridges, ship building,airplane manufacturing and gas pipeline industries. 5)The effective of drilling is much better and quicker than thecommon drill bits.