Patent ID: 7614667

Claim:
An external pipe joint between a pin section and a box section each having an end, the end of the pin and box sections having complementary screw-threaded portions having threads with crests adapted to interengage along the greater part of the axial length thereof, the threads being inclined in the same direction and at an acute angle to the longitudinal axis of the joint, the threads of said box section having a final crest terminating adjacent to a stop shoulder having a frusto-conical head portion which is positioned adjacent a complementary stop shoulder recess on the pin section; the complementary stop shoulder recess comprising a cone receiver having a frusto-conical cross-section and adapted to sealingly receive the frusto-conical head portion; and wherein the box section includes an annular groove comprising two side walls and a recessed bottom wall therebetween, wherein said final crest of said screw-threaded portion of said box section defines one of said side walls of said groove and the stop shoulder of said box section defines the opposite side wall of said groove, said annular groove having a width no greater than the axial distance between the adjacent crests of said threads.