... line with NS-1requirement. Proprietary product——Tool Joint 1.DPDS——Double Shoulder Tool Joint Developed by DP-Master apart from the ... torque capacity increase 30% to 50% than normal API standard tool joint suitable for drilling activities of high pumping pressure,high ... deep and super deep well drilling,directional and horizontal wells2.API Standard Tool JointItem: NC26, NC31 ,NC38, NC40, NC46, NC50, ...