Thread series is hf
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.)
Classification: Nuts of iron or steel
NSN 5996-01-532-2765
NSN 5975-00-266-2029
NSN 6145-00-770-1618
NSN 6105-01-360-9624
NSN 5950-00-405-4275
NSN 4140-01-512-8528
NSN 6135-01-255-9129
NSN 6130-01-287-3931
NSN 5935-00-262-1657
NSN 5945-01-631-9954
NSN 5935-01-072-2293
NSN 7035-01-607-5834