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 5975-01-623-9861
NSN 5905-01-375-4889
NSN 6320-00-432-2772
NSN 6240-01-212-9586
NSN 5905-01-274-9632
NSN 6110-01-342-4253
NSN 6650-00-857-2260
NSN 6130-01-464-0527
NSN 6620-01-243-5281
NSN 6610-01-188-5215
NSN 5905-01-594-1754
NSN 5960-01-217-1479