Closeable opening device for a sealed package

A closeable opening device (1) for a sealed packaging, which contains a flowable medium, wherein the device comprises a spout fitting (2) having a cylindrical pipe section (20) and flange (21), said pipe section being furnished with an internal thread (23) and an external thread (22), as well as a cylindrical cutting element (3), a lower edge of which being equipped with one or a plurality of teeth (35) and an internal jacket surface of which being furnished with driving dogs (37) that protrude in a radial direction and interact with driving dogs (45) in a screw cap (4) comprising a jacket wall (41) and cover surface (40), wherein the spout fitting (2) and the cylindrical cutting element (3) are produced as a one-piece semi-finished good (5) connected to one another via predetermined breaking point bridges (34), characterized in that the cylindrical cutting element (3) has at an upper edge thereof (32) a plurality of recesses (36) uniformly distributed around a circumference and in that ring wall segments (46) diametrically opposite the recesses (36) are integrally formed on the cover surface (40) in the screw cap (4), wherein said ring wall segments, when rotated, are able to slide onto the upper edge (33) of the cutting element (3) until said segments engage in the recesses (36) in the upper edge (33).