| 428 / | HD | STOCK MATERIAL OR MISCELLANEOUS ARTICLES |
| 544 | DF | ALL METAL OR WITH ADJACENT METALS {31} |
| 615 | DF | .~ Composite; i.e., plural, adjacent, spatially distinct metal components (e.g., layers, joint, etc.) {15} |
| 621 | DF | .~.~ With additional, spatially distinct nonmetal component {7} |
| 622 | | .~.~.~ More than one such component {1} |
| 623 | DF | .~.~.~.~> Adjacent to each other |