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 5910-01-140-4710
NSN 7035-01-334-5855
NSN 5905-01-316-8258
NSN 6105-00-093-7415
NSN 6105-01-316-4475
NSN 5965-01-386-2988
NSN 5920-01-057-7494
NSN 7035-01-026-0117
NSN 6220-01-612-2461
NSN 6105-01-592-3213
NSN 5920-01-250-2195
NSN 5915-01-339-0801