A heat exchanger tube, especially for a motor vehicle cooling radiator, comprises a body of oblong cross section defined by two major faces and two minor faces, an end portion of oblong cross section, again defined by two major faces and two minor faces, and a transition portion which joins the tube...http://www.google.com/patents/US5579832?utm_source=gb-gplus-sharePatent US5579832 - Heat exchanger tube, apparatus for forming such a tube, and a heat exchanger comprising such tubes
