Abstract: The invention relates to a method for welding at least one, preferably two metal parts to each other, by a laser beam consisting in using a laser beam (10), a first gas flow and a welding nozzle provided with an output orifice which is passed through by the laser beam and the first gas flow and in welding the part(s) by melting the metal thereof at a point of the laser beam impact with said weldable part(s) in such a way that a capillary (11) or a key hole (12) filled with metal vapour is formed. During welding, the first gas flow is directed only to the aperture of the metal vapour capillary in a direction perpendicular to the weldable part(s) in such a way that a dynamic gas pressure is produced.

Abstract: Gas is blown to protect the weld area (14) by means of a ring nozzle (6) open at the top so as to allow centripetal flow of the gas, deviated by weld work pieces (4, 5), and which then turns back towards the top of the nozzle completing the purge of all ambient gas.