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 
Italy 
Turkey Classification: Gaskets, washers and other seals, of vulcanized rubber other than hard rubber
NSN 6620-01-367-2597
NSN 4140-01-258-1215
NSN 5996-01-246-4675
NSN 5920-01-646-0543
NSN 6130-00-828-7817
NSN 5935-01-204-0336
NSN 6220-01-261-6251
NSN 5920-00-325-3980
NSN 5965-00-267-4173
NSN 5985-00-382-2781
NSN 5950-01-089-9860
NSN 6620-01-196-3548