Abstract: A utility trailer structural panel (10) of the skin-stiffener type has a skin (15) supported by uniformly spaced stiffeners or roof bows (39). Stiffeners or roof bows (39) are secured to panel skin (15) and extend outwardly from the associated panel skin (15). Each stiffener (39) has central flange (35) from which extend webs (36, 37) to mounting flanges (41, 42). Mounting flanges (41, 42) have free edges and respective beads or curls (44, 46) formed thereon for stabilizing of flanges (41, 42) to improve load transfer at the interface between the roof bows (39) and the skin (15).