An exemplary locking cartridge includes a generally cylindrical housing, first and second plates, and a sliding member. The plates are rotatable with respect to the housing, and at least one of the plates is movable in the axial direction of the housing. The housing and the movable plate include cam surfaces that interact to cause the movable plate to move toward the other plate when the movable plate is rotated. The sliding member is slidingly coupled to one of the plates and operable in a blocked state in which the sliding member resists axial motion of the movable plate, and an unblocked state in which the sliding member does not resist axial motion of the movable plate.