... abrasive rock etc. Including impregnated diamond core bit, surface-set diamond bit, reaming shells, casing bit, casing shoe bit, corelifter, corelifter case, core barrel assembly ... in soft to medium hard formation rocks. Size Available: "Q" Series: AQ, BQ, NQ, HQ, PQ (Front end & Back end ... EWT, AWT, BWT, NWT, HWT (Single Tube/Double Tube) WG Series: EWG, AWG, BWG, NWG, HWG (Single Tube/Double Tube) WM ...