Abstract: The present invention relates to a device for the assembling of a plurality of converging tubular bars by means of a central star-shaped core with points which fit into the tube ends, each of the points having means for clamping by expansion in said tubes, the ends of which are in their turn shaped to fit each other in such a way as to completely cover the central core, an entrance being, however, provided in order to act on the clamping means of each point.