Enhance fastener security with our External Tooth Lock Washer, a vital component for preventing loosening in mechanical assemblies. Crafted from durable Phosphor Bronze, this washer guarantees long-lasting performance even in demanding environments. With an outside diameter of 0.6 inches and a thickness of 0.031 inches, it provides reliable reinforcement for 5/16-inch hole sizes. Compliant with ASME B18.21.1 standards and RoHS regulations, it ensures both quality and environmental responsibility. Upgrade your hardware with this essential washer for optimal stability and peace of mind.