A shaft according to the invention for a wheel set, in particular for a rail vehicle, has at least one shaft body which extends along a longitudinal axis. The shaft body has at least one first load coupling portion which is used to introduce and/or discharge a force and/or a torque into or from a functional component, in particular a brake disc of a disc brake, a rail wheel, a wheel set shaft bearing, or a drive gear device. According to the invention, the shaft body consists at least partly of at least one first material in which fibers made of a second substantially non-metal material are at least partly embedded. The shaft body is preferably made of multiple fiber layers, in particular support layers for stabilizing the mechanical structure of the shaft body and functional layers, in particular functional layers with measuring elements for monitoring a state of the shaft body and functional layers for transmitting energy or data. The shaft body according to the invention is more lightweight than conventional shaft bodies, offers an improved vibration damping behavior by means of the support layers, and allows a simplified detection of damage by means of the functional layers.