411 / | HD | EXPANDED, THREADED, DRIVEN, HEADED, TOOL-DEFORMED, OR LOCKED-THREADED FASTENER |
900 | DF | FASTENER OR FASTENER ELEMENT COMPOSED OF PLURAL DIFFERENT MATERIALS {1} |
901 | DF | .~ Core and exterior of different materials {1} |
902 | ![]() | .~.~ Metal core {1} |
903 | DF | .~.~.~> Resinous exterior |