A method for Magnetic Arc welding for metallic materials wherein at least one of the workpieces to be welded has an open cross-section. The method comprises bracing the two workpieces and moving them together, wherein the open cross-section of one workpiece is bridged by a metallic auxiliary part to form a conducting closed region, and after the activation of a magnetic field of a magnet coil system and of the current required for welding, the workpieces are placed with a defined spacing and an electric arc is ignited, the magnetic field of the magnet coil system sets the electric arc in rotation in order to uniformly heat the end surfaces to be welded, and subsequently, the surfaces, which are to be welded, of the workpieces are pressed against one another.