Top Pick Loctite® 2047™ High Lubricity, Large Bolt High Strength Black Threadlocker locks and seals threaded fasteners over 5/8 in diameter and over. This increased lubricity threadlocker reduces friction and allows proper clamp load to be achieved. The high strength properties ensure clamp load is maintained when exposed to vibration. Protracted cure speed allows for torque sequences. High viscosity.