Abstract: An apparatus for performing at least one cycle of screwing and unscrewing of a screwthreaded joint for the assembly of tubes, which enables tightening of the joint with a high level of torque while avoiding damage to the screwthreads. The apparatus comprises two wrenches, each wrench engaging against a component of the joint, with each wrench comprising at least one mobile jaw which is slidable in a chamber. The mobile jaw is formed of a material which undergoes plastic deformation at the stress to which it is subjected in order to tighten or loosen the joint. This apparatus is used for bedding-in components of screwthreaded joints for tubes used in petroleum drilling operations.

Abstract: The invention concerns a process for machining a joint element for steel tubes, intended in particular for the petroleum industry, containing a truncated surface (2) and at least one screw stop.

Abstract: The present invention concerns a new threaded joint for steel tubes, usable in particular in the petroleum industry, which contains a female element equipped with conical threads having an internal screw stop mating and a male element correspondingly threaded with a screw stop having a form corresponding to the female element. The male element stop and the female element stop are each manufactured by cold working using a tool capable of engaging in or on the threads of the corresponding element.

Abstract: The invention provides a process for the determination of the make-up torque to be applied on a joint for pipe, destined to the petroleum industry according to which a reference mark is set on the male element and on the female element, so that when the two reference marks are brought to face each other, the make-up restriction stops (2) on the male element (1) and on the female element come into contact with each other; that after having applied a grease, we proceed to make-up by applying sufficient torque to cause one element to rotate with respect to the other one, at a predetermined angle beyond the point where the reference marks are facing each other, and we proceed to measure the torque; that this operation is repeated on a sufficient number of joints; and that a determination is made of the range of torques to be applied on the joints of this type with the grease that has been used.