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 Navy 
Canada 
Italy 
Turkey Classification: Gaskets, washers and other seals, of vulcanized rubber other than hard rubber
NSN 6105-01-088-0493
NSN 5905-01-492-6521
NSN 6145-01-211-6591
NSN 6135-01-338-2281
NSN 7035-01-122-1264
NSN 6135-00-942-7970
NSN 6145-00-951-0884
NSN 5975-01-401-5355
NSN 5915-00-353-0853
NSN 5835-01-111-9838
NSN 5855-01-474-6820
NSN 5990-01-378-7349