... surface set imp. & oversized China Drilling Geological Equipment ltd., is the main professional manufacturer of drilling tool in china, and specializing in the design and ... . Diamond core bit, reaming shell & shoe bit (syn. and surface-set, PDC)4.Drill tool: hoisting plug, water swivel, ... tube & inner tube wrench, foot clamp,etc. the reaming shells AQ BQ NQ HQ PQ T2 T6, surface set and mpregnated,