... bit, corelifter, corelifter case, core barrel assembly, inner tube head assembly, over shot, hoist plugs, drill rod, casing pipe etc. With ... it is used to couple the drill bit with the core barrel. Its main function is ... also acts as a stabilizer for drill bit. Reaming shells (with double pads or three pads) are suitable ... , EWT, AWT, BWT, NWT, HWT (Single Tube/Double Tube) WG Series: EWG, AWG, BWG, NWG, ...