A device for fastening a tool member on an output shaft of a power tool has a support plate supporting the tool member and a clamping element embodied as a connecting hub. The connecting hub is penetrated by the output shaft and is rotationally fixed on the output shaft. A rider plate is secured on the connecting hub and rotatable relative to the connecting hub. Support plate, tool member, rider plate, and connecting hub are arranged such that the output shaft projects through support plate, tool member, rider plate, and connecting hub. A clamping device is carried on an end of the output shaft. The clamping device acts on a support surface of the connecting hub and fixes through the connecting hub the tool member on the support plate. Connecting hub, rider plate, and pressure plate together form preferably a conjoint, connected component assembly.
