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 5915-01-540-9757
NSN 5985-00-708-2193
NSN 5855-01-641-2736
NSN 2925-00-757-7028
NSN 5990-01-074-6549
NSN 5855-00-252-5743
NSN 5999-01-109-4990
NSN 6145-01-438-7322
NSN 4140-00-074-4242
NSN 5905-00-661-2395
NSN 5910-01-444-1429
NSN 6240-01-037-7108