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 5855-00-147-2508
NSN 6650-01-620-5877
NSN 6645-01-193-9839
NSN 5960-01-219-5504
NSN 6320-01-170-4068
NSN 5925-01-337-4928
NSN 6650-00-266-6808
NSN 6620-00-965-9841
NSN 5999-00-391-5541
NSN 6145-01-603-1659
NSN 5960-01-150-3944
NSN 5990-01-616-9342