Abstract: Process for permanently fastening the end or ends of at least one rod, made at least partially of a thermoplastic material and having at least one continuous cavity, in at least one opening of a support plate. The opening surrounds at least one rod, with each rod - in order to be fastened - positioned in its designated opening in the support plate. Each rod cavity exhibits a hydraulic diameter which corresponds to at least 10% of the minimum outside cross-sectional dimension of the rod, and the rod walls may exhibit pores which take up a maximum of 20% of the wall volume.

Abstract: The invention comprises a method and apparatus wherein an insert, preferably made of plastic and preferably allowing a melt-on bonding with the tubes and whose floor has a traversing opening for each tube, is inserted into the first part of the injection mold (top mold or bottom mold) as a positioning element for the tubes in such a manner that the insert is at least partially locked or secured into the first part of the injection mold. A tube is then placed in each opening of the insert. A mandrel is then placed in each tube, whereupon the injection mold is locked in such a manner that, if necessary, the mandrels are locked into the second part of the injection mold (bottom mold or top mold). A molten thermoplastic material is then injected, via a sprue provided in the injection mold, into a cavity formed by the injection mold, the insert and the tube ends.