Thread Sealant ? medium strength. For fine threads in hydraulic, pneumatic and general fittings. Fast curing. LOCTITE 542 is designed for the locking and sealing of metal pipes and fittings as well as other cylindrical metal assemblies. The product cures when confined in the absence of air between close-fitting metal surfaces and prevents loosening and leakage due to shock and vibration. The thixotropic nature of LOCTITE 542 reduces the migration of liquid product after application to the part. Ideal for fine threads as used in hydraulic, pneumatic general fittings Instant low-pressure seal Suitable for metal threads only Resistant to fuel, oil, coolants and hydraulic fluids Locks connection against vibration loosening