Nut, hex, heavy duty (requested name)
A nut, flat on top and bottom having 6 flat sides. For items which have internal tapered or straight (parallel) pipe threads, specific electrical conduit size designation, and which when installed, provide a method of tightening to lock the connection, see locknut, electrical conduit. See also locknut, tube fitting. For items having a thickness (or height) exceeding two times the width across the flats, use post, electrical-mechanical equipment. (when height or thickness and/or width across the flats is designated as a tolerance dimension, the maximum dimension will be used to determine compliance.)
NSN 5935-01-364-0359
NSN 6110-01-137-7981
NSN 5835-00-936-8753
NSN 6645-00-819-5045
NSN 6240-01-112-7577
NSN 7035-00-486-0367
NSN 6105-01-487-5072
NSN 5998-00-296-3570
NSN 5965-01-058-1414
NSN 6105-00-319-5897
NSN 7035-01-309-6709
NSN 5855-00-973-5717