Method of cold forming an elongated hollow article

Claim 1

THE PROCESS FOR MAKING A FERROUS METAL SPARK PLUG SHELL WHICH COMPRISES CUTTING A CYLINDRICAL BLANK FROM ROD STOCK, PRESSING THE CUT BLANK AXIALLY IN A DIE HAVING A GRADUALLY REDUCED DIAMETER TO PARTIALLY POINT ONE END OF THE BLANK, THEREAFTER EXTRUDING SAID PARTIALLY POINTED END OF THE BLANK FOR LESS THAN HALF OF THE LENGTH OF THE BLANK AND AXIALLY PRESSING THE BLANK FROM OPPOSITE ENDS TO FORM A RECESS IN THE UN-EXTRUDED END OF THE BLANK, THEREAFTER EXTRUDING SAID EXTRUDED END OF THE BLANK A SECOND TIME AND PIERCING SUBSTANTIALLY UNWORKED METEL OF SAID BLANK ADJACENT THE RECESSED END OF THE BLANK OUTWARDLY INTO A HEX DIE, THEREAFTER EXTRUDING SUBSTANTIALLY UNWORKED METAL OF THE BLANK BETWEEN THAT PORTION WHICH HAS BEEN SPREAD INTO A HEX DIE AND SAID EXTRUDED END OF THE BLANK ALONG AN EXTRUDING PUNCH TO FORM A CYLINDRICAL CUP IN THE MAJOR PORTION OF THE BLANK, AND THEREAFTER PUNCHING OUT THE WEB FROM THE PORTION OF THE BLANK WHICH WAS TWICE EXTRUDED.