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} |
655 | DF | .~.~ Transition metal-base component {4} |
660 | DF | .~.~.~ Refractory (Group IVB, VB, or VIB) metal-base component {3} |
663 | DF | .~.~.~.~ Group VIB metal-base component {3} |
665 | .~.~.~.~.~ W-base component |