Abstract: A rotary die-cutting apparatus having cylindrical rollers mounted for rotation on spaced parallel axles. Die plates are mounted on the rollers in tight surface-to-surface contact with the outside surfaces thereof. Each roller has a body with a generally cylindrical outside surface and two longitudinal channels formed therein. The die plates are formed as thin flexible sheets of metal having their ends welded to one of the bars for mounting the sheets on the outside surface of the rollers. A wedge-shaped bar is slideably mounted in the other channel. After the ends of the die plate are welded to the weld bar in butting relation, the die plate is mounted on the roller with the wedge bar removed from its associated channel. After the plate is mounted on the roller, the wedge bar is slid into the channel and gradually forced against the die plate to bring it into surface-to-surface contact with the roller.