Abstract: To connect two pipes together, a female end-piece (1) is fitted thereon comprising an annular seal housed in an annular cup (2) and a pin (6) guided in transverse slides (9) and, respectively, a male end-piece ending in a collar and adapted to crush the seal axially. The pin comprises two arms (8) whose end sections (8.sub.2) allow the collar to pass axially and whose base sections (8.sub.1) on the contrary serve for clamping the collar axially against the seal, these base sections ending in ramps (R) facilitating the beginning of cooperation between the arms and collar. Hooks (12) limit the outgoing travel of the pin.