Tubular connection

In a pipe joint including pin and box members, the joint having an axis,

• a. annular shoulders on the members having sealing interfit, and
• b. first and second interengaged threads on the respective members, the threads having dovetail interfit and locking the members together against relative separation proximate one axial side of said annular shoulders, each thread having progressively changing axial width along substantially the entire helical length thereof at selected radial distance from said axis, whereby upon complete make-up of the joint the interengaged thread flanks produce forces tending to urge the members radially together.

In a joint including pin and box members, the joint having an axis,

• a. a pair of interengaged threads on said members for producing circumferential tension in the pin member and circumferential compression in the box member in response to forcible make-up of said members,
• b. the threads on said members having dove-tail interfit,
• c. said thread on each member having progressively changing axial width along substantially the entire helical length thereof and at selected radial distance from said axis, whereby upon complete make-up of the joint the interengaged thread flanks produce forces tending to urge the members radially together.