Hillman 300024 Split Lock Washer, 3/8 in ID, Hardened Steel, Zinc-Plated

Engineered to provide more uniform load distribution, split lock washers are great for any indoor and outdoor project. Ideal for situations where potential loosening from corrosion or vibration is a concern, split lock washers are used to prevent nuts and bolts from coming loose. These fasteners contain split ends that help lock into the mating material, thus providing a locking feature when tightened beneath a nut. The zinc finish provides moderate corrosion resistance. Use with treated lumber in applications with like nuts and bolts of similar diameter.