This study carried out circumferential welding experiments in tubes with 3.68 mm thick. Welding was performed using MIG welding equipment with CMT Cold Metal Transfer?? control and with the aid of Motoman robot and a turntable. This was to ensure the accurate positioning of the torch and that the welding was fully implemented in the 1G position, respectively. The weld joints were then evaluated visually, and the joints which present fully penetration were then subjected to tensile testing, microhardness Vickers test and metallography. The welding performed, has shown a lack of penetration for all parameters performed when welded by CMT conventional process. To avoid this problem, the weld was performed using the CMT process combined with pulsed arc, thus creating greater energy during welding, resulting in full penetration and improved surface finish. For this process which has provide fully penetration, the mechanical tests and the metallographic tests were performed and has present adequate results.