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 6135-00-182-7008
NSN 6135-01-177-3552
NSN 6130-00-266-7496
NSN 5910-01-339-1296
NSN 5935-01-476-7306
NSN 6645-01-422-9672
NSN 4140-01-313-7756
NSN 5965-01-079-7939
NSN 6130-01-165-2130
NSN 5905-01-516-7443
NSN 6220-00-686-5328
NSN 5855-00-004-0904