ABSTRACT
Liquid sealants include retaining compounds, thread-sealing adhesives, and thread-locking adhesives [15, pp. 130, 137]. Retaining compounds are normally anaerobic or cyanoacrylate adhesives. They fill the voids in the threaded assemblies and then chemically harden. In many cases, the assembled fasteners may become permanently bonded. The threads are sealed, and they become vibration-resistant, protected from corrosion, and leak-free. Thread-sealing adhesives also fill the gaps between the threads of an assembled fastener and provide a level of thread locking. These materials are often used to seal threads on pipe joints. Thread-locking adhesives are intended to provide a level of breakout torque. These adhesives come in a variety of strengths and formulations depending on the application. The popular formulations are one part solvent-based chemical curing, one part anaerobic, two parts curing, and "passivated" preapplied adhesives. The primary function of thread-locking adhesives is thread locking. Thread-sealing performance will vary with manufacturer and formulation. See Chapters 22 and 23 for more information on thread sealants.
