LOCTITE^® 5400 is a medium-strength thread sealant for locking and sealing all metal threaded fittings up to M80/R3", but is also suitable for other cylindrical metal assemblies. This yellow to dark orange, dimethacrylate ester acrylic paste cures when confined in the absence of air between close fitting metal surfaces and prevents loosening and leakage from shock and vibration. It fluoresces under UV light – great for quality control. LOCTITE 5400 will not creep, shrink or block systems by shredding and is designed to provide an instant low-pressure seal even at low temperatures. It carries no hazard symbols, risk or safety phrases and doesn’t contain any declarable carcinogens, mutagens or reproductive toxins. It's also resistant to fuel, oil, coolants and hydraulic fluids.