Prime-Line #6 Zinc Plated Steel Internal Tooth Lock Washers (50-Pack)

Internal tooth lock washers feature teeth that help to prevent loosening of a nut or bolt by digging into the surface. For maximum holding power, use 1 between the surface and the bolt head and use another 1 between the surface and the nut. It is best to use these with smaller bolt heads and in applications where there is a desire to not have exposed teeth. Lock washers are great for use in cases where the bolt may be subject to vibration.