Abstract: Apparatus and method for cutting an end portion of a carton blank, e.g. to form a stitch flap, employs a rotatably driven male cutting head cooperating with a rotatably driven female cutting head. The female cutting head has a peripheral cutting groove therein and an anvil surface adjacent one side of the groove. The male cutting head has a two edged slot cutting blade of predetermined arcuate length which enters the groove each revolution, and a knife which extends transversely away from the blade and engages the anvil surface each revolution. The blade has a scallop-like cut-out in the side adjacent the anvil surface. The cut-out modifies the blade to a single edged cutting blade for a small part of its length. Scrap portions produced from the carton blank by a slotting cut of the blade and a transverse cut of the knife are integrally connected together by a bridging piece enabled by this cut-out.