Disclosed is a tube 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 includes a first wall and a second wall forming two opposing sides of the tube, and a plurality of reinforcing structures connecting the first and second walls and forming longitudinal passages between them. Each reinforcing structure is formed by a longitudinal ridge on the first wall projecting towards the second wall and a longitudinal ridge on the second wall protecting towards the first wall. The ridges are joined to each other at their sides.