HEAT EXCHANGER

The invention relates to a heat exchanger, in particular exhaust-gas cooler or charge-air cooler, comprising a plate stack composed of multiple elongate plate pairs, wherein in each case two interconnected plates form a first fluid duct between them, and a second fluid duct is formed between two plate pairs, wherein the plates of a plate pair are of U-shaped form with a bottom and upturned side walls and lie against one another so as to delimit the first flow duct, wherein one of the plates of a plate pair has, on its end side, a tab which serves for beading over around the end side of the other plate, wherein the tab on the bottom of the plate is beaded over, and the beading-over of the tab also continues into the side walls of the plates.