3/8" x 45/64" Zinc Plated Grade 2 Steel Internal Tooth Lock Washers (60 pcs.)

Diameter: 3/8"
Diameter 2: 45/64"
Thickness: 1/16"
Material: Steel
Finish: Zinc
Hardness: Grade 2
Nominal Size: 3/8"
Style: Internal Tooth
Type: Lock Washer
Application: Smaller head screws

Box of 60.

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