LOCTITE^® 569 is a hydraulic-grade thread sealant designed for the locking and sealing of fine threaded metal pipes and fittings. The low-to-medium viscosity product cures when confined in the absence of air between close-fitting metal surfaces, and prevents loosening and leakage from shock and vibration when cured. It contains no fillers or particles that could contaminate system fluids, foul valves, or clog fine filters and screens.