Abstract: The invention concerns a steel tube threaded joint particularly useful in the petroleum industry of the type in which the male element (3) and female element (1) are combined by threading (2, 4) wherein a portion of the surface of each thread is forcefully applied to the status of screwing to the thread of the outer element. A first element (1) of the joint has a composite structure and has on at least a certain length of its thread a lining of synthetic material whose volume and shape correspond exactly to the volume and shape of the existing clearance of the screwing status between the metal part and composite element (1) and the second element (3) having dimensions at the limit of the machining tolerances which allow the greatest possible clearance in the assembled state of the joint.

Abstract: A threaded joint for steel pipes useable in particular for the petroleum industry is provided. The joint is formed by threaded male and female elements wherein one part of the thread of a first element is strongly applied against the thread of the other element. One of the elements contains a groove having a length of at least one thread pitch and a depth greater than the height of the threads. A sealing device is provided in the groove consisting of a synthetic lining whose volume and shape essentially correspond to the volume and shape of the play that would exist between the threads of the elements.

Abstract: Joint for pipes of the type in which an end of a male member (1) provided with a thread is screwed into a female member (2) having a corresponding thread.On its outer surface, the male member has a circumferential groove (9) and on the inner surface the female member has a circumferential groove (10) which, in the screwed position, faces the groove of the male member. A spring ring (12) is provided to simultaneously engage in the said grooves. At least one of the grooves has an adequate radial depth to permit the retraction of the spring ring when the male member is engaged in the female member.