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 5895-01-421-4487
NSN 5855-01-497-8834
NSN 6320-01-335-8336
NSN 5965-01-544-3081
NSN 6685-01-634-0611
NSN 6220-01-293-9365
NSN 6650-00-139-5459
NSN 6220-01-111-7085
NSN 6130-01-338-7216
NSN 5925-01-416-0913
NSN 5990-01-148-3324
NSN 5835-00-647-2104