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 Army 
Dept. of the Air Force 
U.s. Marine Corps Classification: Washers other than lock washers, iron or steel
NSN 6685-01-325-9274
NSN 6130-01-415-3345
NSN 5996-01-400-3558
NSN 6650-01-243-5291
NSN 4140-01-389-0595
NSN 5935-01-295-6923
NSN 5996-01-024-9976
NSN 5996-01-331-6875
NSN 5925-00-877-8066
NSN 5990-01-532-0670
NSN 6145-01-565-8605
NSN 5925-01-336-1928