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 
Greece Classification: Gaskets, washers and other seals, of vulcanized rubber other than hard rubber
NSN 6650-00-496-8762
NSN 5835-00-341-5441
NSN 5835-00-269-2232
NSN 7035-00-361-5975
NSN 6320-01-039-5891
NSN 5990-00-995-6071
NSN 7035-01-319-7066
NSN 6645-01-595-7659
NSN 5998-00-516-9344
NSN 6130-01-398-3313
NSN 2925-01-236-3547
NSN 5935-01-374-9390