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 6685-01-173-1506
NSN 6620-01-397-8683
NSN 5945-01-539-1076
NSN 5996-01-618-1746
NSN 4140-01-546-6150
NSN 5855-00-918-1622
NSN 5950-00-846-3744
NSN 6685-01-201-0916
NSN 5998-01-223-0882
NSN 6110-01-429-8668
NSN 6105-01-268-8150
NSN 6220-01-350-8014