Diameter: 6.4mmDiameter 2: 11mmThickness: 1.6mmMaterial: SteelFinish: ZincHardness: Class 8Type: Flat WasherSpecifications: SAEA flat washer is a thin, usually round, plate with a hole in the middle that is normally used to distribute the load of a threaded fastener. USS flat washers have a large, wider body. SAE flat washers are machined to a tighter specification and have a smaller outside diameter.