Header box, heat exchanger comprising said header box and method of crimping such a box

A manifold comprises a collector and a cover having a dimension with longitudinal extension and further comprises at least one flange crimped between the collector and the cover;

• wherein the collector has ductility which is greater than that of the flange;
• and wherein at the flange, a longitudinal portion of the collector has a first thickness which is smaller than a thickness of a remainder of the longitudinal portion of the collector and a first length, and at the flange, the longitudinal portion of the collector is rolled such that the longitudinal portion of the collector is tapered, has a rounded pointed terminal end, and has a second length which is longer than the first length,
• wherein the collector has a base which is a bottom portion of the collector and wherein the base of the collector has a constant thickness, and
• wherein the flange is blocked between the collector and the cover,
• wherein the flange has a foot part against which the collector is rolled, wherein the collector has lateral wings which are rolled against the foot part of the flange, and wherein the lateral wings are rolled such that the lateral wings have a free longitudinal edge with a thickness which is smaller than the remainder of the longitudinal portion of the collector, wherein the base of the collector is provided with flattened slots which are bordered by collars.