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 5935-01-162-0520
NSN 5925-01-484-3201
NSN 6110-00-271-9928
NSN 5920-01-233-3770
NSN 6650-00-211-6302
NSN 5965-01-005-0341
NSN 5985-01-315-3284
NSN 6650-00-597-7313
NSN 5998-01-242-6782
NSN 4140-00-707-5963
NSN 7035-01-007-0241
NSN 6145-01-541-9085