411 / | HD | EXPANDED, THREADED, DRIVEN, HEADED, TOOL-DEFORMED, OR LOCKED-THREADED FASTENER |
378 | DF | EXTERNALLY THREADED FASTENER ELEMENT, E.G., BOLT, SCREW, ETC. {16} |
386 | DF | .~ Pilot end having means enhancing fastening or installation {1} |
387.1 | DD | .~.~ Drill-tip-type end {5} |
387.3 | .~.~.~ Having enhanced gripping structure |