Process of producing bolts

Claim 1

THE PROCESS OF PRODUCING A HEADED ARTICLE FROM A WROUGHT BAR OF AN AUSTENITIC ALLOY HAVING CHROMIUM AND AT LEAST ONE OF THE ELEMENTS SELECTED FROM THE GROUP CONSISTING OF NICKEL, IRON AND COBALT AS THE BASE METAL THEREOF AND CONTAINING A PRECIPITATION HARDENING CONSTITUENT, THE WROUGHT BAR HAVING A SUBSTANTIALLY UNIFORM GRAIN SIZE AT LEAST AS FINE AS NO. 4 ASTM, THE STEPS COMPRISING, WORKING THE WROUGHT BAR AT A TEMPERATURE BELOW THE RECRYSTALLIZATION TEMPERATURE OF THE ALLOY TO EFFECT A REDUCTION IN AREA OF FROM 10% TO 25% AND INTRODUCE WORK HARDENING THEREIN HEADING THE BAR AT A TEMPERATURE BELOW 1650* F. TO PRODUCE A HEAD THEREON, SOLUTION TREATING THE HEADED BAR AT A TEMPERATURE BETWEEN 1750* F. AND 2300* F. FOR A PERIOD OF TIME BETWEEN 1/2 AND 4 HOURS TO RECRYSTALLIZE THE ALLOY WHEREBY TO REMOVE WORK HARDENING THEREFROM AND TO PRODUCE A SUBSTANTIALLY UNIFORM GRAIN SIZE THROUGHOUT THE HEAD AND THE BAR, QUENCHING THE HEADED BAR, AND AGEING THE QUENCHED HEADED BAR AT A TEMPERATURE BETWEEN 1200* F. AND 16000* F. FOR A PERIOD OF TIME BETWEEN 20 AND 100 HOURS.