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 6650-00-891-4534
NSN 6220-01-294-3377
NSN 6135-01-616-0696
NSN 5960-00-965-5055
NSN 5935-00-576-7316
NSN 5960-00-153-7115
NSN 5905-01-503-2608
NSN 5945-00-894-2142
NSN 2925-01-012-3162
NSN 2925-01-599-1901
NSN 5905-01-431-9807
NSN 6135-01-322-4655