In one example in accordance with the present disclosure an apparatus for attaching to a shaft using a wedge is described. The apparatus includes a disc having a longitudinal axis. At least a portion of the disc is insertable into a shaft and is expandable against an inside diameter of the shaft. The disc has a recess at the longitudinal axis. A wedge to be inserted into the recess pushes the portion of the disc that is insertable into the shaft against an inside diameter of the shaft.