5/16" x 45/64" Chrome Grade 8 Internal Tooth Lock Washers (10 pcs.)

Diameter: 5/16"
Diameter 2: 45/64"
Thickness: 1/16"
Material: Steel
Finish: Chrome
Hardness: Grade 8
Nominal Size: 5/16"
Style: Internal Tooth
Type: Lock Washer
Application: Smaller head screws

Box of 10.

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