Product Description Keeps Lock Nuts include a hex nut with a pre-assembled, free-spinning external tooth lock washer. They should be used in low-load assemblies to ensure a lasting, reliable hold for any project. These nuts have an external star washer attached and when tightened, they bite into a soft surface thus providing a locking action. They are zinc-plated and rust/corrosion resistant. From the Manufacturer Keps Lock Nuts include a hex nut with a pre-assembled, free-spinning external tooth lock washer. They should be used in low-load assemblies to ensure a lasting, reliable hold for any project. These nuts have an external star washer attached and when tightened, they bite into a soft surface thus providing a locking action. They are zinc-plated and rust/corrosion resistant.