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 5855-01-382-8725
NSN 6220-00-249-4751
NSN 5999-01-497-6974
NSN 6240-00-406-7335
NSN 6145-01-460-4357
NSN 5998-01-381-5375
NSN 6130-00-821-3500
NSN 2925-01-565-6410
NSN 5910-01-628-4935
NSN 6145-01-156-0284
NSN 6645-00-968-6118
NSN 6320-00-853-1920