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 6650-01-437-6279
NSN 5998-00-536-4873
NSN 5935-00-548-5440
NSN 6650-01-103-7342
NSN 5960-01-046-8308
NSN 5920-01-351-9822
NSN 6645-00-880-8045
NSN 6650-00-957-9985
NSN 6610-00-278-7647
NSN 5915-01-407-4559
NSN 4140-01-558-1862
NSN 5960-01-196-9203