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 5999-01-400-3590
NSN 5905-00-734-6386
NSN 5945-01-048-3780
NSN 5910-00-044-7175
NSN 6130-00-138-6042
NSN 5835-00-551-3050
NSN 6105-00-111-2546
NSN 5996-01-113-4612
NSN 6145-01-346-6219
NSN 2925-01-448-1277
NSN 5855-01-308-0955
NSN 6105-01-559-4579