Abstract: A bottle closure cap stampable from sheet metal as a shallow cylindrical inverted dish having a rounded juncture forming a fillet between its crown and its cylindrical wall; a layer of elastomeric material being disposed in the fillet and engageable with the axial end of the bottle when the cap is attached. A generally radially extending rip tab is integral with the cylindrical wall at the bottom edge thereof and is adapted to tear through the cylindrical wall by a generally circumferential pull of the user to gain access to the container. A rip line is provided commencing at a corner defined by the bottom edge of the cylindrical wall where it meets the rip tab. At least one groove is formed in the rip tab extending in the inner surface of the side wall. The rip line extends at a shallow angle across the cylindrical wall, without crossing the groove, continuing to a level which is spaced below the crown, continuing parallel to the crown circumferentially about half-way around the closure cap.