| 148 / | HD | METAL TREATMENT |
| 95 | DF | PROCESS OF MODIFYING OR MAINTAINING INTERNAL PHYSICAL STRUCTURE (I.E., MICROSTRUCTURE) OR CHEMICAL PROPERTIES OF METAL, PROCESS OF REACTIVE COATING OF METAL AND PROCESS OF CHEMICAL-HEAT REMOVING (E.G., FLAME-CUTTING, ETC.) OR BURNING OF METAL {17} |
| 559 | DF | .~ Heating or cooling of solid metal {22} |
| 579 | DF | .~.~ Iron(Fe) or iron base alloy {24} |
| 660 | DF | .~.~.~ Including cooling (e.g., quenching, etc.) {3} |
| 662 | DF | .~.~.~.~ Heating step follows cooling {1} |
| 663 | | .~.~.~.~.~ Tempering |