Abstract: A fitting or fitting assembly is provided that comprises a fitting body having an enlarged first end, a nut having a circumferential ridge that has a diameter less than the first end of the fitting body so that the first end prevents the nut from sliding further in one direction, and a ring that is adapted to be assembled onto the exterior surface of the fitting body to prevent the nut from sliding further in a second direction opposite to the first direction. The nut has interior threads that are adapted to receive the external threads of a mated fitting. A method for assembling the fitting comprises the steps of sliding a nut having an internally threaded portion onto a fitting body having an enlarged end that prevents axial movement of the nut in a first direction, and press-fitting a retention ring about the fitting body at a desired position in order to limit the axial movement of the nut in a second direction opposite to the first direction.