... high quality alloy tube.3m &1.5m, with multi-heat treat, China Drilling Geological Equipment ltd., ... is the main professional manufacturer of drilling tool in china, and specializing in the design ... drilling)We produce a wide range of drilling tool including drill rod, wireline core barrel (AQ- ... bit (syn. and surface-set, PDC)4.Drill tool: hoisting plug, water swivel, overshot (standard,heavy duty ...