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 6320-00-521-9350
NSN 5930-01-588-2224
NSN 5999-00-735-9865
NSN 5996-01-281-7336
NSN 5945-00-636-9813
NSN 5998-00-583-8617
NSN 5975-01-454-1600
NSN 5965-01-459-4345
NSN 5996-01-009-5482
NSN 5835-01-426-0069
NSN 5910-00-500-9622
NSN 6110-01-468-0157