Flat washers distribute the load of a fastener over a wider surface area, helping protect the material and prevent damage as the fastener is tightened.

Nominal Size: 5/16"
Inside Diameter: 11/32"
Outside Diameter: 11/16"
Thickness: 1/16"
Material: Steel
Finish: Yellow Zinc
Thread Type: SAE
Hardness: Grade 8
Type: Flat Washer
A 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.