... CNC machines,and made of high quality alloy. 3m &1.5m, multi-heat treat. include BT NT HT China Drilling Geological Equipment ... diamond surface-set core bit, PDC bits (core or noncoring), casing shoes, reaming shells, overshot, hoisting plug, water swiel, wrench ... . 1.Drill rod: BQ, NQ , HQ, PHD, BT, NT, HT and BW, NW, HW casing tube: BW, NW, HW ...