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 
National Security Agency 
U.s. Marine Corps 
Dept. of the Navy 
Federal Aviation Administration
Federal Aviation Administration 
U.s. Coast Guard 
National Weather Service 
National Aeronautics and Space Administration
National Aeronautics and Space Administration
National Aeronautics and Space Administration 
Austria 
Finland 
Lithuania 
Poland 
Brazil 
Spain 
Columbia 
Israel 
Singapore 
Kuwait 
Morocco 
Saudi Arabia 
Malaysia 
Australia 
Belgium 
Canada 
South Africa 
New Zealand 
France 
Germany 
Republic of Korea 
United Kingdom 
Netherlands 
Portugal 
Italy 
Denmark 
Norway 
Greece 
Turkey 
NATO Maintenance and Supply Agency Classification: Nuts of iron or steel
NSN 5935-01-063-6450
NSN 7035-01-384-9257
NSN 5910-01-240-2951
NSN 6110-01-427-0161
NSN 5855-01-497-0467
NSN 5905-01-318-1674
NSN 5985-01-444-0825
NSN 6650-01-373-4159
NSN 6150-01-227-2595
NSN 5920-00-624-3049
NSN 6240-00-151-7642
NSN 5915-01-452-4249