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 7035-01-477-4181
NSN 6320-01-506-9439
NSN 5975-01-223-2470
NSN 5950-00-814-6817
NSN 6650-01-463-2274
NSN 6220-01-295-2022
NSN 5990-00-110-9441
NSN 6105-01-418-7760
NSN 6105-01-212-3394
NSN 5910-00-100-5784
NSN 5965-00-722-7574
NSN 6610-00-113-4552