In a method for joining two, in particular rotationally symmetrical, metal parts (1, 2) by a tungsten inert gas (TIG) welding process, in a first step, the two metal parts (1, 2) to be joined are initially positioned relative to one another by a centering offset (7) in such a way that a narrow gap (4) is formed between them and a relief region (8) is created in the seam-bottom area. In a second step, the flanks (5, 6) of the metal parts (1, 2), which delimit the narrow gap (4), are joined together by welding beads (10) which fill the narrow gap (4), with a predetermined melt-through point (9) being formed. High-quality automatic welding is achieved in that the narrow gap (4) has a continuously constant width (a), in that the width (a) of the narrow gap (4) is selected such that the welding beads (10) lying one above the other each extend over the entire width (a) of the narrow gap (4), and in that the entire narrow gap (4) is filled with the welding beads (10) in fully automatic fashion.