The invention relates to a plain bearing composite material provided with a metallic support layer, optionally with a porous carrier layer applied thereto, and with a lead-free sliding layer, which forms a sliding partner and whose sliding layer material is based on plastic. The hub is bonded to the data storage disk, and the metal hub plate allows the disk to be magnetically clamped to a spindle of a disk drive. A warehouse system receives the order data, such as to allow a warehouse operator to make plans for accommodating the order, and the shipment data, such as to notify the warehouse operator of actual amounts of goods that have been shipped. The pusher rod is longitudinally releasably attachable to the piston at a plurality of locations along the length of the pusher rod and is located to engage the rotor when the base is coupled to the stator tube.