CPC Subgroup
C21D 9/36 for balls; for rollers
Full Title
Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor > for balls; for rollers
C21D 9/36 Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor > for balls; for rollers