The present invention relates to a tube (1) made of a profile rolled metal product, in particular for use in heat exchangers, a rolled metal product and a method of producing the same. The tube (1) includes a first wall (2) and a second wall (4) forming two opposing sides of the tube, and a plurality of reinforcing structures connecting the first and second walls (2, 4) and forming longitudinal passages (10) between them. Each reinforcing structure is formed by a longitudinal ridge (6) on the first wall (2) projecting towards the second wall (4) and a longitudinal ridge (8) on the second wall (4) protecting towards the first wall (2). The ridges (6, 8) are joined to each other at their sides.