Called nut
No other part numbers with same form, fit, and function found.
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 7035-01-649-4434
NSN 5960-01-344-2604
NSN 6685-01-468-5781
NSN 6105-00-307-3690
NSN 6610-01-501-6630
NSN 5999-00-255-3871
NSN 5935-01-137-0336
NSN 6650-01-562-9944
NSN 6610-01-219-1656
NSN 5975-00-318-1637
NSN 5835-00-537-7780
NSN 6220-01-351-9046