The Security Locknut resists vibration loosening under the most extreme conditions. Designed so that the steel insert raises away from the nut body upon application. This creates "isolation" from the load: the nut body carries the load and the insert does the locking. Security Locknuts can be adjusted, readjusted, removed, repositioned, and reused as often as required. Heat resistant up to 400[DEG]C (750[DEG]F). Easy installation, no special tools required (prev. no. SH539Z) Vibration resistant: Holds bolted joint tight in extreme vibration conditions Easy installation: No special tools required. Doesn"t require special machining operations, pins, or holes Locks in any position on bolt: No clamping torque necessary to achieve locking function Re-usable: Consistent performance when adjusted, readjusted, removed, repositioned, and reused as often as required Extreme conditions: Effective in temperatures to 400[DEG]C (750[DEG]F) and in high acidic or other chemical environments