Abstract: A bow beam, as well as a method of making the beam for the roof of truck trailer, is described as being initially extruded in a U-shape with a flat web which is heavier than a pair of legs which extend from the web. The extruded beam is then placed in a press where the free ends of the legs are bent to form a bow in the topside of the beam in spaced relation from the flat bottom web. Thus, the strength of the beam is optimized with a minimal amount of material.