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.)
Dept. of the Navy NSN 6240-00-865-7447
NSN 5945-01-357-7118
NSN 6645-00-126-0286
NSN 5930-01-267-3974
NSN 5910-01-097-7664
NSN 5999-01-091-7296
NSN 5985-01-552-4174
NSN 6110-01-295-4828
NSN 5998-01-165-3234
NSN 5985-01-336-3483
NSN 5920-01-252-2353
NSN 6645-01-425-2330