gaugeable tube fittings and adapter fittings 55 tools and accessories gap inspection gauge swagelok gap inspection gauges assure the installer or inspector that the fitting has been sufficiently pulled up on initial installation whether using a multihead hydraulic swaging unit mhsu or air-actuated hydraulic swaging unit ahsu or wrench tightening all metal swagelok tube fittings are gaugeable with the exception of a few forged bodies in aluminum for installation using the ahsu fitting size in 1/4 3/8 1/2 mm ordering number female nut ms-ahsu-ig-468 6 8 10 12 ms-ahsu-ig-612m for installation ...