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 Army 
Dept. of the Air Force 
U.s. Marine Corps 
Dept. of the Navy 
U.s. Coast Guard 
National Aeronautics and Space Administration
National Aeronautics and Space Administration 
Austria 
Lithuania 
Poland 
Brazil 
Spain 
Kuwait 
Morocco 
Thailand 
Australia 
Canada 
New Zealand 
France 
Germany 
Republic of Korea 
United Kingdom 
Netherlands 
Portugal 
Italy 
Denmark 
Greece 
Turkey Classification: Nuts of iron or steel
NSN 5835-01-237-3769
NSN 5930-01-598-0346
NSN 6110-01-083-7524
NSN 5920-01-324-0517
NSN 5855-01-416-1088
NSN 6110-01-196-3560
NSN 5990-01-118-0151
NSN 6240-01-399-4105
NSN 5895-01-391-6785
NSN 5835-01-150-6084
NSN 5985-01-313-6892
NSN 5999-01-171-5297