Sheet metal joint

Claim 1

IN A CONTAINER MEMBER HAVING A WALL FABRICATED FROM SHEET STOCK; TEAR LINE MEANS FORMED IN THE MEMBER AND DEFINING A WEAKENED ELONGATE SECTION; MEANS TO ACCOMMODATE FORCE APPLICATION TO THE SECTION TO INDUCE FRACTURE OF THE SECTION FROM THE MEMBER COMPRISING A TAB WITH AN APERTURE THEREIN; AND A PERMANENT CONNECTION BETWEEN THE TAB AND THE SECTION COMPRISING A GENERALLY HOLLOW RIVET PROJECTING FROM AND INTEGRAL WITH THE SECTION, AND EXTENDING THROUGH THE APERTURE IN THE TAB, SAID HOLLOW RIVET HAVING A PERIPHERAL WALL AND A TRANSVERSE END WALL, SAID END WALL BEING THINNER THAN THE PERIPHERAL WALL, SAID END WALL AND THE PERIPHERAL WALL BEING INTEGRALLY JOINED BY A CIRCUMSCRIBING SINGLE-LAYER BEAD OVERLYING AND CLAMPINGLY ENGAGING THE RIM OF THE APERTURE, SAID BEAD AS MEASURED RADIALLY OF THE HOLLOW RIVET BEING AT LEAST AS THICK AS THE PERIPHERAL WALL OF THE HOLLOW RIVET, SAID BEAD BEING OF HOLLOW CONFIGURATION IN CROSS SECTION AND BEING SHAPED WITH AN INNER RADIUS SPACING THE TRANSVERSE END WALL OF THE HOLLOW RIVET FROM THE PERIPHERAL WALL OF THE HOLLOW RIVET.