A fitting for the connection of a tubing end. The fitting includes a body having a bore with an internally-threaded opening which extends to a seating surface, and a front ferrule which is receivable coaxially over the tubing end. An externally-threaded nut is receivable coaxially over the outer diameter of the tubing end to be positionable thereon rearwardly of the front ferrule such that, with the tubing end and front ferrule being inserted through the bore opening, the nut is threadably engageable with the body urging an outer surface of the ferrule into a canning engagement against the body seating surface. The axial length of the seating surface is provided to extend substantially the entire length of the ferrule outer surface so as to constrain the radial outward expansion of the ferrule rearward end.