Abstract: A fitting for attachment to a tube by swaging comprises a cylindrical sleeve having a tapered outer surface and an inner surface for receiving the tube. A cylindrical swaging ring having a tapered inner surface engages the tapered outer surface of the sleeve such that axial movement of the ring in a forward direction with respect to the sleeve causes the ring to apply a radial force to the sleeve to swage it to the tube. The swaging ring is locked onto the sleeve both before and after swaging by one or more protrusions on the outer surface of the sleeve which cooperatively engage an annular groove in the swaging ring. The location of the protrusions and groove in relation to the tapered surfaces on the swaging ring and sleeve is especially configured to provide smooth axial loading during swaging and increase tube retention capabilities at the conclusion of the swaging operation.