Midwest Fastener 3/8 in. Internal Tooth Lock Washer

The Midwest Fastener 3/8 in. Internal Tooth Lock Washer is engineered to prevent nuts, bolts, and other threaded fasteners from loosening under vibration or dynamic loads. The internal teeth bite firmly into mating surfaces, establishing a secure grip that resists back-off across demanding hardware applications. Constructed from Grade 2 steel with a protective zinc finish, this internal tooth lock washer provides dependable mechanical strength and corrosion resistance. It is well-suited for automotive, home improvement, and general fastening projects requiring long-lasting locking performance.