Piston rod for a cylinder

The piston rod (20) for a cylinder, especially a clutch master cylinder in a motor vehicle, has a reciprocating piston attached to one end, and fastened to the other end has a fastening device (1) to connect the piston rod to the clutch pedal via a damping disc (52). The fastening device is movable back and forth in the longitudinal direction of the piston rod via a guide which comprises a guide pin (43) of round cross section which extends through the damping disc. An independent claim is included for a cylinder, especially a clutch master cylinder of a motor vehicle, which includes the aforesaid piston rod.