... all manufactured by CNC machines and made of high quality alloy tube, 3m &1.5m, multi-heat treat. China Drilling Geological ... 3.AQ,BQ,NQ,HQ,PQ, BTW, NTW, T2, T6 etc. Diamond core bit, reaming shell & shoe bit (syn. and surface ... , water swivel, overshot, outer tube & inner tube wrench, foot clamp,etc.