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 6620-01-486-8002
NSN 6320-00-433-2773
NSN 5925-00-523-0377
NSN 6645-01-177-6021
NSN 5965-01-434-3464
NSN 5999-01-459-8452
NSN 6145-01-101-6178
NSN 6320-01-019-1028
NSN 6135-01-244-5580
NSN 5930-01-191-3284
NSN 5960-01-604-1158
NSN 5965-01-261-6073