CPC Subgroup
C21D 9/12 barrels for ordnance
Full Title
Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor > for tubular bodies or pipes > barrels for ordnance
C21D 9/12 Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor > for tubular bodies or pipes > barrels for ordnance