| 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} |
| 566 | DF | .~.~ Electric heating with work as conductor (e.g., alternating current, induction, etc.) {2} |
| 567 | DF | .~.~.~ Induction {6} |
| 573 | | .~.~.~.~ Gear, threaded article, drill or serrated work surface (e.g., saw blade, etc.) |