Abstract: A spool assembly comprises a spindle formed as a tubular section having an inner surface and two end faces. A guiding notch is furnished in each end face of the spindle. A locking opening is furnished near each end of the spindle. The spool assembly further comprises two flanges. Each flange includes a disk and a hub. Each hub is centeredly and fixedly attached to each disk and has a tubular shape such that an outer face of each hub matches the inner surface of the spindle. A guiding member protrudes outwardly from each hub for engaging a respective one of the guiding notches to rotate the spindle relative to each hub into a proper aligned position with respect to each hub as the spool assembly is assembled. A locking member is provided on each hub for engaging a respective one of the locking openings such that, upon insertion of each hub into a respective end of the spindle, a connection between the hubs and the spindle is obtained which is stable against pulling forces in an axial direction.