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: 4mm
Inside Diameter: 4.3mm
Outside Diameter: 7.8mm
Thickness: 1mm
Material: Steel
Finish: Zinc
Hardness: Class 8
Type: Flat Washer
Specifications: SAE
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.