BQ NQ HQ PQ inner tube wrench & outer tube wrench,full hole wrench, diamond coated China Drilling Geological Equipment ltd., is ... hydra-power station grouting project (wireline core drilling and double-tube core drilling ).1.Drill rod: BQ NQ HQ PQ NT ... , PDC)4.Drill tool: hoisting plug water swivel overshot outer tube & inner tube wrench foot clamp etc. HQ inner tube full hole wrench,diamond