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 6145-00-233-6010
NSN 7035-00-887-4674
NSN 5915-01-246-3380
NSN 5910-01-392-6757
NSN 6610-01-309-5361
NSN 6105-01-534-8992
NSN 5855-01-546-2810
NSN 5950-00-055-1747
NSN 5915-01-607-1055
NSN 5945-01-326-2729
NSN 6145-01-599-9935
NSN 4140-00-484-4040