The process of welding using Gas Metal Arc Welding (GMAW) has been developed so that the productivity of welding is increased. Types of welding used one of them use welding GMAW tandem (T-GMAW) tack weld. T-GMAW tack weld is a welding process combined the use of two welding GMAW process that produces a weld pool of the same and use of the tack weld so that the material will be in las not changed position. The purpose of this study is to investigate the influence of the distance between the welding electrodes against the distortion and mechanical properties of the material AA 5083 H116 welded T-GMAW. This study uses Aluminum AA 5083 H116 with a thickness of 3 mm and welding of T-GMAW tack weld using distance between the electrodes 18 mm, 27 mm, and 36 mm. The welding conditions voltage, torch angle, welding speed, the flow rate of argon gas was made the same on both welding machine. After the welding process, the testing performed includes measuring the distortion, microstructure observation, the measurement value of the Vickers hardness, tensile test, and bending test Based on the results of testing the welding of T-GMAW tack weld shows that the specimens with. the distance between the electrodes of 18 mm has the properties of the physical and mechanical. The farther the distance between the electrodes will then the longer the cooling rate that resulted in granules which are formed increasingly larger and the effect on hardness and tensile strength. The result of the distortion of the largest maximum occurs in the specimen with a distance between electrodes is 27 mm amounted to 14,225 mm. The highest hardness value was shown by specimens with the variation of the distance between the electrodes of 18 mm with the value of the VHN 80,75. Maximum tensile strength (ultimate tensile strength) and the value of the bending strength with the distance between the electrode 18 by 262,11 Mpa and the bending strength of 492,41 Mpa on the part of the face bending.