Loctite 545 hydraulic, pneumatic sealant thread sealant is a pipe sealant designed for the locking and sealing of metal pipes and fittings. This product is specially formulated to offer high lubricity for easy assembly and removal. - It contains no fillers or particles that could contaminate system fluids, foul valves or clog fine filters and screens. Recommended for fine threaded fittings as used in hydraulic and pneumatic installations and small fittings in general.