Abstract: A unitary assembly of tubing and an end fitting. The end fitting comprises a threaded fastener fitting having a tubular bore extending therethrough. An undercut annular groove is coaxially provided in the wall portion of the tubular bore which is spaced apart from the end of the fitting. The opening of the tubular bore at the end of the fitting is provided with an undercut counterbore. The end of the tubing is inserted through the opening and into the tubular bore until it engages a stop formed by a reduced diameter portion of the tubular bore at the axially inward end of the undercut annular groove. A ball mandrel is inserted through the opening at the other end of the tubular bore to engage and force the end portion of the tube into the undercut annular groove. A braze ring is inserted into the undercut counterbore the latter of which allows a braze fillet to form during the brazing operation.