DIFF Subgroup
C21D 1/613 Gases; Liquefied or solidified normally gaseous material
Introduced: January 1980
Full Title
General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering > characterised by the quenching agents > Gases; Liquefied or solidified normally gaseous material
No child classifications to compare. This is a leaf node in both IPC and CPC.