Stop socket head screws from loosening due to mild vibration. These washers have a small diameter to fit under screws with narrow heads, but are still thick enough to keep fasteners secure. While they're not as vibration resistant as other lock washers, they are a great fit for electrical panels, light fixtures, and other light duty assemblies. Split lock washers are not reusable, and they only work with fasteners that have right-hand threads. Also known as high-collar lock washers.

The wavy shape flexes like a spring to keep nuts and screws secure on slightly uneven surfaces. These washers add a small amount of tension to stop fasteners from backing out due to mild vibration. While they don't hold as well as other lock washers, they do grip slightly better than curved washers. They work best in electrical panels, light fixtures, and other light duty assemblies. Since these washers hold their shape when untightened, you can reuse them a handful of times without losing strength.