Enhance the security of your fastening system with this Internal Tooth Lockwasher. Crafted from durable Phosphor Bronze, it ensures long-lasting performance in various environments. With an outside diameter of .682 inches and a thickness of .036 inches, it provides a reliable grip on your assembly. The internal tooth design offers superior locking capabilities, preventing loosening due to vibration or movement. Designed for easy installation, it has an inside diameter of .391 inches and is compatible with a 3/8-inch hole size. Trust in this high-quality lockwasher for efficient and secure fastening in your projects.