Enhance the security of your fastening applications with this Internal Tooth Lockwasher. Crafted from durable 410 Stainless Steel, it offers reliable performance in various environments. With an outside diameter of .278 inches and a thickness of .017 inches, it effectively grips onto surfaces to prevent loosening. The inside diameter of .133 inches and hole size #5 make it compatible with a range of screws and bolts. Rest easy knowing it complies with RoHS standards for environmental responsibility. Upgrade your fastening system with this essential component.