Abstract: Improved internal tooling for a swaging apparatus for attaching fittings to tubing. The tooling includes a draw bolt having a head at one end adapted to be connected to actuating means such as a hydraulic cylinder at its opposite end. A straight cylindrical resilient expander sleeve is coaxially disposed on the draw bolt and is bracketed by a pair of split, circular, anti-extrusion rings located in mating seats formed in facing end surfaces of the draw bolt head and a seal bushing. The facing surfaces of the head and bushing are further configured to include a ramp surface extending between the surface of the draw bolt and split ring seats.