Abstract: A coupling for mandrels in winding machines wherein the mandrel has a square end portion receivable in a complementary cavity which is machined into a socket rotating with a shaft which drives the mandrel in a direction to collect or to pay out a web of flexible material. The socket has a hand wheel which is movable between operative and inoperative positions and the remaining part of the socket carries one or more cushions in the form of pads and/or pins which are urged against the end portion of the mandrel when the hand wheel is moved to the operative position. Additional cushions can be provided on the hand wheel. The mandrel and the socket are further provided with cooperating centering elements for the mandrel. The cushion or cushions prevent wobbling of the mandrel and reduce noise when the mandrel is driven by the shaft.