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 5985-00-291-9974
NSN 5930-01-521-5202
NSN 6110-00-544-2527
NSN 6620-00-104-6937
NSN 7035-01-276-0355
NSN 5905-00-272-3476
NSN 5925-01-592-3077
NSN 5835-01-332-2867
NSN 6240-01-370-5242
NSN 5915-01-344-9692
NSN 6645-00-860-3657
NSN 5855-01-459-9254