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 6240-01-273-0193
NSN 2925-01-218-5556
NSN 5855-01-653-7718
NSN 5915-00-188-4054
NSN 5835-01-252-5879
NSN 5930-00-781-4000
NSN 6240-01-572-6003
NSN 5950-01-630-2394
NSN 5905-01-508-8015
NSN 5950-01-275-9352
NSN 5975-01-207-8190
NSN 5920-01-594-2424