<p>Invention relates to a quick-clamping arrangement for the upper knife in a slitter winder, where the upper knife of the slitter winder is locked into its place by pressing the upper knife by a retaining cap (52) against a support flange (48) arranged on the shaft (6) of the upper knife, where the hub (54) of the upper knife is provided with a hub disc (56) that is movable by means of pressure fluid against spring pressure and where the end portion (68) of the hub is provided with a groove (70) for the retaining cap (52). The joint between the retaining cap (52) and the hub (54) is rotationally form-locked.</p>
