Abstract: A joint of the integral type includes a male element 1 and a female element 2 with a diameter close to that of the tubes. Each of the elements has two shifted frustoconical threaded sections 4, 5, 6, 7 with vanishing threads at the two ends, by virtue of convergences of frustoconical envelope surfaces 16, 17, 18, and 19 and cylindrical surfaces 20, 21, 22, 23. A central abutment 24 cooperates with the negative-flank threads to reinforce the male/female connection and two internal 27 and external 28 ring-shaped metal/metal tightness zones, preventing the penetration of fluid into the threaded zones from the ends. The threaded joint may be used with tubes for very deep wells for which the reduction of the diameter of the assemblies makes it possible to lower costs, and other tubes for which a problem of the same type may arise.