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 5965-00-970-6431
NSN 6135-00-542-6728
NSN 6685-00-014-6081
NSN 5910-01-245-5311
NSN 4140-01-125-2906
NSN 5925-01-291-5508
NSN 6145-01-142-9463
NSN 6240-01-239-9916
NSN 5960-00-515-7366
NSN 6610-01-184-9700
NSN 4140-01-473-2527
NSN 5920-01-660-9295