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.

Diameter: 1/2"
Diameter 2: 1-1/4"
Thickness: 5/64"
Material: Steel
Finish: Zinc
Thread Type: USS
Hardness: Grade 2
Nominal Size: 7/16"
Type: Flat Washer

Diameter: 13/16"
Diameter 2: 2"
Thickness: 5/32"
Material: Steel
Finish: Zinc
Thread Type: USS
Hardness: Grade 2
Nominal Size: 3/4"
Type: Flat Washer

Diameter: 11/16"
Diameter 2: 1-3/4"
Thickness: 9/64"
Material: Steel
Finish: Zinc
Thread Type: USS
Hardness: Grade 2
Nominal Size: 5/8"
Type: Flat Washer