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 6135-01-061-1862
NSN 5925-00-659-3456
NSN 5915-00-035-8590
NSN 5855-01-163-8152
NSN 5990-00-201-1162
NSN 6145-00-256-3984
NSN 5910-00-800-5054
NSN 5960-01-123-8775
NSN 6150-00-099-6919
NSN 6320-00-925-0558
NSN 5965-01-069-0391
NSN 6145-01-431-6834