The item is a flight safety critical aircraft part (fscap).
A washer having a centrally located hole with a solid or laminated cross-section and two flat parallel bearing surfaces. The hole must be 75 percent or less than the largest dimension and the bearing surface finish is greater than 32 microinch (0.8 micrometer). The thickness cannot exceed 25 percent of the largest outside dimension. When the largest outside dimension is less than 1/4 inch or 6mm, the thickness must be 0.006 inches (0.15mm) or greater and for items 1/4 inch (6mm) or larger, the thickness must be 0.016 inches (0.4mm) or greater. The maximum tolerance is applied to dimensions and used as a determining factor. Items with separable lamination use shim. For items fabricated from ceramic or electrically rated materials by specification or industry standards use insulator (1), washer. Excludes disk, valve, graphite impregnated and lubricated items.
Dept. of the Army 
Dept. of the Air Force 
U.s. Marine Corps 
Dept. of the Navy 
Federal Aviation Administration 
U.s. Coast Guard 
National Aeronautics and Space Administration
National Aeronautics and Space Administration
National Aeronautics and Space Administration 
Bosnia and Herzegovina 
Sweden 
Austria 
Finland 
Lithuania 
Slovenia 
Poland 
Romania 
Slovakia 
Bulgaria 
Czech Republic 
Brazil 
Spain 
Columbia 
Singapore 
Kuwait 
Morocco 
Malaysia 
Australia 
Belgium 
Canada 
New Zealand 
France 
Germany 
Republic of Korea 
United Kingdom 
Philippines 
Netherlands 
Portugal 
Italy 
Denmark 
Norway 
Greece 
Turkey 
NATO Maintenance and Supply Agency Classification: Cotters, cotter-pins, washers and similar articles, of aluminum
NSN 5915-01-056-6287
NSN 5915-01-628-0895
NSN 6130-01-196-6391
NSN 5999-00-286-6231
NSN 5835-01-391-4556
NSN 6645-01-472-5623
NSN 6650-01-301-3310
NSN 5950-01-438-7330
NSN 6610-01-393-2388
NSN 5975-00-226-8429
NSN 6150-01-413-1866
NSN 5945-00-243-9365