The invention concerns a header plate, preferably for a heat exchanger, such as water cooled charge air cooler (WCCAC), comprising a coolant housing having two opposing walls made up from two header plates (11, 12), which are made of sheet metal of a defined thickness (t). The header plates (11, 12) form parts of air tanks and are passed by air tubes extending through said coolant housing from one of said header plates (11, 12) to the other. The header plates (11, 12) have stamped apertures (15), in which said air tubes are inserted and tightly connected to the header plate sheet metal. The apertures (15) have peripheral rims (22), which protrude on one side of the header plate (11, 12) in question and give an extra support to the air tubes inserted in the apertures (15) of said header plate (11, 12). The distance (da) between adjacent apertures (15) and thus the distance (dt) between adjacent air tubes is less than two times the thickness (t) of the header plate sheet metal.