Lock washers add spring tension or bite beneath a fastener head or nut, helping resist loosening from vibration.
Nominal Size: 4mm
Inside Diameter: 4mm
Outside Diameter: 6.8mm
Thickness: .5mm
Material: Steel
Finish: Zinc
Style: Safety
Type: Lock Washer
The purpose for a lock washer is to prevent threaded fasteners from loosening by creating friction between the fastener and the mounting surface.