| C | SK | CHEMISTRY; METALLURGY |
| C22 | KL | METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS |
| C22B | UKL | PRODUCTION OR REFINING OF METALS (making metallic powder or suspensions thereof B22F 9/00; production of metals by electrolysis or electrophoresis C25); PRETREATMENT OF RAW MATERIALS |
| C22C | UKL | ALLOYS (treatment of alloys C21D, C22F) |
| C22F | UKL | CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS OR NON-FERROUS ALLOYS (processes specific to heat treatment of ferrous alloys or steels and devices for heat treatment of metals or alloys C21D) |