Apparatus and method for aligning wire conductors (11a, 11b) extending from coil members (11) inserted in slots of a core (10) of an electric dynamo machine to join the ends (11'a,11'b) of the wire conductors by means of a welding operation accomplished by welding means (30), comprising : a first member (41) having a plurality of passages (40); a second member (42) having a plurality of passages (40'); the first and second members (41,42) being assembled adjacent to each other to align in pairs the passages (40) of the first member (41) with the passages (40') of the second member (42); each pair of aligned passages (40,40') forming a single passage capable of receiving at least the end portions (11a, 11b) of two conductors; the first member (41) and the second member (42) being relatively moved in the circumferential direction (C) of the core to cause the sides of the passages (40,40') to engage and move the end portions (11a, 11b) of the wire conductors in the circumferential direction (C); a thrust in the radial direction (R) of the core being exerted on inclined portions (I) of the wire conductors to cause the end portions (11a, 11b) of the wire conductors present in a single passage to engage each other in the radial direction (R) and the portion of wire conductor most distant in the radial direction in the single passage to engage the sides of the single passage in the radial direction (R).