Conelok Nuts are a type of prevailing-torque locknut or self-locking nut. They are frictionally resistant to rotation due to localized precision deformation of the thread in the cone section on top of the nut. Grade C Conelok Locknuts are all steel one piece construction. Lock in any position and are strong, shock-proof and vibration proof. Easily installed and reusable - starts freely and then requires wrenching as the out-of-round gripping threads engage the bolt. Grade C nut strength is similar to Grade 8. Zinc plated fasteners have good corrosion resistant qualities and are a good choice for indoor, outdoor and industrial applications.