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 6135-01-562-6582
NSN 5998-01-200-2050
NSN 5920-00-137-5025
NSN 5920-00-466-3950
NSN 2925-00-774-8247
NSN 6150-01-363-9299
NSN 6240-00-428-4027
NSN 4140-00-044-1329
NSN 5950-01-430-3338
NSN 5999-00-258-2601
NSN 6685-01-376-5751
NSN 6620-01-443-3526