a cutting and / or creasing die includes a sheet which is to be bent around and attached to a roller of a rotary machine for producing blanks from a strip of material , particularly for producing creased blanks for boxes from cardboard or similar material . the method of the invention includes forming the sheet with a plurality of tongues bent out of the general plane of the sheet to the side thereof which will face away from the roller when in operation , and laterally of the lines which indicate the desired positions of a plurality of cutting and / or creasing blades . the blades have lateral projections and , after they have been positioned along the lines , the tongues are bent into forced contact with the lateral projections of the blades , thus attaching the latter to the sheet . the blades may be bonded to the sheet prior to the bending of the tongues . finally , the sheet with the blades attached thereto is mounted on the roller .