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 5960-01-553-4557
NSN 5895-01-300-9569
NSN 5935-01-177-1680
NSN 5975-01-378-2882
NSN 5930-01-432-5774
NSN 5965-01-118-6302
NSN 5930-00-157-4559
NSN 6240-00-292-3237
NSN 6145-01-101-4900
NSN 5855-01-343-7943
NSN 6685-01-466-7828
NSN 6685-01-416-8991