HIGH TORQUE TOOL JOINT

摘要

In the tool joint of the drill pipe having a pair of female screw threads (4) and male ones (3) at the opposite ends thereof, shoulder parts (5) are formed respectively on the outer surface side of the male threaded part and the inner surface side of the female threaded part so that: joint parts may be in plane contact with each other at two places; a length from the shoulder part formed on the pipe body side of each threaded part to the foremost end is made shorter than an engaging depth of the shoulder part of the general purpose tool joint as well as than the engaging depth of the female threaded side of said joint; and a clearance at inner shoulder parts is made 0 to 0.5 mm when tightened by hand. In contrast with the conventional API tool joint having an external shoulder, a tool joint of this invention is additionally provided with an internal shoulder to withstand excessive torque acting thereon while being used and interchangeable with the API tool joint.