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 
Canada 
Italy 
Turkey Classification: Gaskets, washers and other seals, of vulcanized rubber other than hard rubber
NSN 6130-01-027-2839
NSN 5960-00-593-5603
NSN 6685-00-006-1968
NSN 6650-01-166-5025
NSN 6650-00-295-1749
NSN 5998-00-880-3561
NSN 5905-00-099-9995
NSN 6650-01-042-3564
NSN 6145-01-385-3454
NSN 6130-01-646-0893
NSN 6620-01-633-8443
NSN 5950-01-463-3096