Abstract: 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.