Metallic container closure having internal pressure release

A metallic container closure comprising a shell of a thin metal sheet having a circular top panel wall and a cylindrical skirt wall hanging down from a circumferential edge of the top panel wall, and a synthetic resin liner arranged in the shell, the skirt wall of the shell having a thread-forming region and an annular groove positioned at an upper end portion of the thread-forming region, wherein:

• an internal pressure release line inclusive of a slit extending in the circumferential direction is arranged in the skirt wall at a portion over the annular groove, and an annular bead is arranged so as to pass through between the internal pressure release line and the annular groove;
• wherein the annular bead extends in the horizontal direction, and
• wherein a knurling is formed over the annular groove of the skirt wall and the internal pressure release line is formed at the upper end of the knurling.