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 6650-01-658-4145
NSN 5930-01-421-8036
NSN 5975-00-557-4829
NSN 4140-00-224-8417
NSN 5835-01-202-9673
NSN 6320-01-622-5493
NSN 6150-00-306-2020
NSN 5930-00-342-2525
NSN 5996-01-432-0117
NSN 6240-01-601-3108
NSN 7035-01-627-8718
NSN 6105-01-044-4123