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 5965-00-870-1980
NSN 7035-00-360-2008
NSN 2925-00-483-9357
NSN 6145-01-192-5227
NSN 5930-01-545-6417
NSN 6610-00-879-2788
NSN 4140-00-580-0716
NSN 6685-00-444-6500
NSN 5998-00-521-7829
NSN 5985-01-172-7344
NSN 5905-01-413-2947
NSN 5985-01-614-1968