Abstract: A device for the linear butt welding of thin metal sheets without weld filler materials comprising movable welding heads, a clamping device having at least two pressing elements which operate independently of one another at least one of the pressing elements being suitable for applying two or more distinct pressure levels and additional horizontal pressing elements are further provided in order to press the metal sheets to be welded against one other while being deformed, until full-area contact of the metal-sheet edges butting against one another is achieved as well as a welding method making use of the device.