Diameter: 3/16"
Diameter 2: 27/64"
Thickness: 3/64"
Material: Steel
Finish: Zinc
Hardness: Grade 2
Nominal Size: #10 (3/16")
Style: Internal Tooth
Type: Lock Washer
Application: Smaller head screws

Box of 100.

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