A closure cap made of deep-drawable material, in particular aluminium, is characterized in having reinforcing beads (6) incorporated in the wall (3) of the closure cap (1). Said beads are arranged at a distance apart along a spiral and form the screw of the closure cap (1). As a result of the continuous strip-shaped regions (7) between the reinforcing beads, the closure cap possesses very high stability, which precludes the possibility of a blow off, i.e., the closure cap will not pop out in the event of overpressure in the container.