Abstract: A mounting device for easily and quickly locking a roll of material wound around an elongated core between two supporting arms of a roll supporting device is disclosed. The mounting device comprises a tubular member provided with a fastener for fastening the tubular member to one of the arms. The mounting device also comprises a shaft slidably mounted through the tubular member. The shaft has first and second ends extending outside the tubular member. The first end of the shaft is provided with a handle and the second end of the shaft is provided with an engaging member for engaging with an end of the core. The shaft is movable relative to the tubular member between a locking position wherein the engaging member is pushed against the end of the core, and an unlocking position wherein the engaging member is withdrawn from the end of the core. The mounting device further comprises a locking device operatively associated with the tubular member and the shaft for locking the shaft into the locking position.