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 5910-01-386-3191
NSN 5985-00-916-7333
NSN 6145-01-452-4437
NSN 6150-01-101-7323
NSN 5965-01-651-3108
NSN 6240-01-396-8962
NSN 5990-00-469-2604
NSN 6620-01-542-8709
NSN 5999-01-277-1683
NSN 6110-01-325-1884
NSN 5999-00-568-2845
NSN 5975-01-020-9860