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 5915-01-573-5980
NSN 4140-01-113-6415
NSN 6110-01-312-1981
NSN 5895-00-542-2019
NSN 5999-01-005-7307
NSN 5945-00-068-4311
NSN 6110-00-479-0403
NSN 4140-01-588-6189
NSN 5915-00-886-5474
NSN 5950-00-290-8090
NSN 6135-01-535-9092
NSN 6220-00-790-9574