1/4" x 31/64" Black Chrome Plated Grade 2 Steel Lock Washers

Diameter: 1/4"
Diameter 2: 31/64"
Thickness: 1/16"
Material: Steel
Finish: Black Chrome
Hardness: Grade 2
Nominal Size: 1/4" (#14)
Style: Medium Split
Type: Lock Washer

Box of 15.

The purpose for a lock washer is to prevent threaded fasteners from loosening by creating friction between the fastener and the mounting surface.