Abstract: A spool assembly of simple, lightweight construction affording efficient, balanced, and inexpensive operation is constructed simply of a pair of end flanges secured to the ends of a hollow exterior tube on which material, such as carpet yarn, may be wound. The tube has interior, longitudinally extending, integral projections that provide longitudinal slots in which self-tapping screws are secured with the heads of the screws retained in the end flanges to secure the flanges on the tube. The slots may be formed by pairs of inwardly projecting walls with the walls retained against spreading by end reinforcing plugs disposed in the ends of the tubes and having peripheral notches that encompass and retain the projecting walls. Alternatively, an interior reinforcing core may be disposed in each end of the tube with radial arms extending partially into the slots for cooperation with the projecting walls to receive and retain the screws.