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 
Turkey Classification: Gaskets, washers and other seals, of vulcanized rubber other than hard rubber
NSN 6645-01-312-3558
NSN 2925-01-485-8304
NSN 6610-01-611-5323
NSN 6685-01-055-6057
NSN 4140-01-154-9615
NSN 6145-01-363-1925
NSN 6130-01-185-2770
NSN 5930-01-227-2870
NSN 5925-00-104-5761
NSN 6685-01-592-6863
NSN 6150-01-494-6531
NSN 5895-00-371-1644