POWERLOK II® fasteners would be recommended for this application. POWERLOK® is our all metal TRILOBULAR™ fastener for use in tapped nut members. The POWERLOK® screw achieves enhanced locking ability through the combination of a novel 60° - 30° thread form and a TRILOBULAR™ thread body. The 30° tip penetrates the root of the nut threads as the thread form locking feature. POWERLOK® screws resist vibration even when unseated as the locking feature extends the entire length of the fastener; therefore POWERLOK® fasteners make excellent adjusting screws.