Abstract: The invention relates to a rotatable supporting element for accommodating winding tubes, plug-in adapters or the like with a supporting body and a casing, which surrounds the supporting body and is connected with it indissolubly in sleeve fashion and comprises a material which is different from and has a greater hardness than that of the supporting body. The casing has at least one stress-relieving region which extends in ring-shaped fashion about its periphery and is formed by a region of reduced material thickness or by a material-free region. By means of this configuration, stress peaks in the casing and uncontrolled tearing or breaking of the casing are avoided.