Ensure optimal fastening security with this Internal Tooth Lockwasher. Crafted from durable steel with a protective zinc coating, it offers reliable performance in various applications. The .6-inch outside diameter and .031-inch thickness provide a snug fit, while the precise .326-inch inside diameter accommodates a 5/16-inch hole size. Compliant with RoHS regulations, this lockwasher combines quality and environmental responsibility for peace of mind. Trust in its effectiveness for your fastening needs.