Welding of spot-like metal parts can be made carried out using an electric arc generated by a high potential difference between an electrode and the welding spot. The generating system allows to trigger the arc without needing any contact of the parts, controlling the current supplied and the welding time, to assure an optimal control of the temperature generated at the welding spot. MARSILLI has been working for a long time with MacGregor Welding Systems to supply its customers the most suitable technological solution.