A spool assembly has a central cylindrical barrel or tube portion formed from a substantially rectangular planar material, such as thin-gauge sheet aluminum or tin-plated steel, with beveled corners. The formation of the barrel from the substantially rectangular planar material results in a seam with shallow V-notches of the seams at the opposite ends of the barrel. A circular flange sub assembly is attached to each end of the barrel and extends radially outwardly perpendicular to the longitudinal axis of the barrel. Each flange sub assembly comprises an outer flange and an inner flange core joined by an annular ring or curl that defines a circular hub recess or cavity for receiving the respective end of the barrel. A portion of the seam at the end of the barrel is secured within the circular hub recess or cavity; whereby the flanges are keyed onto the ends of the barrel, thereby preventing circumferential slippage of the flanges on the barrel.