Screw connection device for conduits, in particular for motor vehicle conduits

The device has a cap nut (2) having an inner space (3) and an internal thread (4). A terminal element has an external thread (6) encircling over circumference of inner space. A pipe line end (7) of a pipe line (1) received in the cap nut includes a front-sided portion (8). A stop face (9) is moveably arranged toward back surface (10) of the front-sided portion during screwing of the internal thread of cap nut with the external thread of terminal element in inner space of cap nut. A spring element (11) is arranged between the stop face and back surface over pipe line.