... the main professional manufacturer for drilling tools Core barrel: BQ,NQ,HQ,PQ , BQU, NQU backend assembly , China Drilling Geological ... of outstanding quality and satisfied service.1.Drill rod: BQ, NQ, HQ , PQ , NT, HT, BW, NW, HW Casing tube: ... BW, NW, HW, HWT2.Core barrel: BQ NQ NQ2 NQ3 HQ HQ3 PQ PQ3 head assembly and parts3 ... wrench, foot clamp,etc. Casing Cutter BW NW HW NQ HQ PQ