Medium-strength, general purpose thread sealant for straight/straight and straight/taper threads and fittings. Fills the space between threaded parts and seals and locks at the same time.LOCTITE 577 is designed for the locking and sealing of metal pipes and fittings as well as other threaded assemblies. The product provides an instant, low-pressure seal for metal pipes and fittings. It will not creep, shrink or shred. It has excellent chemical and thermal resistance and offers less migration of liquid product after application.