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 6650-01-573-7165
NSN 5960-01-060-4375
NSN 5930-01-294-6643
NSN 6130-01-333-8592
NSN 5950-00-554-4870
NSN 6610-00-914-8929
NSN 6220-01-472-2998
NSN 4140-01-176-0228
NSN 5910-01-377-2630
NSN 5999-01-431-7050
NSN 5935-01-116-0351
NSN 5910-00-144-4383