5/16" x 45/64" 18-8 Stainless Internal Tooth Lock Washers LWSS-114 (16 pcs.)

Diameter: 5/16"
Diameter 2: 45/64"
Thickness: 1/16"
Material: Stainless Steel
Hardness: 18-8
Nominal Size: 5/16"
Style: Internal Tooth
Type: Lock Washer
Application: Smaller head screws

Box of 16.

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