A rotary part, in particular a spreader roller for a web-processing machine has a supporting core with a longitudinal axis, said supporting core being mounted at its two longitudinal ends, and having an elastically flexible outer sleeve which surrounds the supporting core in its circumferential direction and extends, in at least some sections, between the two longitudinal ends of the supporting core. The outer sleeve on the supporting core is non-displaceably mounted on at least one bearing and that the outer sleeve is mounted on at least one displacing point at a distance from the bearing so as to be displaceable perpendicular to the longitudinal axis of the supporting core in order for the curvature of the outer sleeve to be adjustable.