A flat metal or plastic item of various peripheral shapes having a solid (not laminated) cross-section. It is designed to maintain a predetermined distance between two surfaces. For round items without a hole having a solid rectangular cross-section use disk, solid, plain. For round or hexagonal items with only one hole centrally located and with the length (thickness) exceeding 25 percent of the outside diameter or distance across peripheral flats, see spacer, sleeve. The thickness between the two parallel bearing surfaces must be 0.006 inch, (0.152 mm) or more for items less than 1/4 inch (6.35 mm) across the peripheral diameter, or smallest overall outside dimension, or must be 0.016 inch (0.406 mm) or more for items 1/4 inch (6.35 mm) or greater across the peripheral diameter or smallest overall outside dimension. For items with a thickness less than those indicated above, see shim. For items with one hole centrally located conforming to the above dimensional criteria use washer, flat or spacer, ring as applicable. When thickness and/or outside diameter or smallest overall outside dimension is designated as a tolerance/dimension the maximum dimension will be used to determine compliance. Excludes gasket; insulator (as modified) and mounting pad, electrical-electronic component.
Dept. of the Navy 
Spain 
Turkey Classification: Copper screws, nuts, bolts, rivets, and other fasteners not threaded
NSN 5996-01-155-2467
NSN 5965-01-359-8172
NSN 5925-01-087-4854
NSN 2925-00-347-7893
NSN 6105-01-280-5343
NSN 5965-00-532-3284
NSN 7035-01-092-5723
NSN 6620-00-996-8026
NSN 5905-01-194-4232
NSN 5960-00-931-8172
NSN 6145-00-318-9206
NSN 5975-01-524-4969