... are all manufactured by CNC machines, and made of high quality alloy,3m &1.5m,with multi-heat treat,BW ... station grouting project ( wireline core drilling and double-tube core drilling)We produce a wide range of drilling ... BQ, NQ , HQ, PHD, BT, NT, HT casing tube: BW, NW, HW, HWT2.Core barrel: BQ,NQ,HQ, ... water swivel(compact plus and standard), overshot, outer tube & inner tube wrench, foot clamp,etc.