Loctite 545 Purple Hydraulic & Pneumatic Thread Sealant

LOCTITE® 545™ is a purple, medium-viscosity anaerobic thread sealant formulated for locking and sealing metal hydraulic and pneumatic pipes and fittings. It cures when confined without air between close-fitting metal surfaces, helping prevent leakage and loosening caused by shock and vibration. Its lubricating formulation also supports easier assembly and wrench tightening.

Primary Features & Benefits:

• Designed specifically for metal hydraulic and pneumatic fittings
• Locks and seals threaded connections to help prevent leaks
• Resists loosening caused by shock and vibration
• Medium-viscosity formula fills thread voids while remaining easy to apply
• Provides lubricity for easier assembly
• One-component anaerobic chemistry requires no mixing
• Properly tightened fittings seal immediately against moderate pressure
• Activator can accelerate curing on inactive metals or in larger gaps

Typical Applications:

• Hydraulic pipe fittings and threaded fluid-power connections
• Pneumatic fittings, air lines, valves, regulators, and manifolds
• Industrial machinery and process-equipment piping
• Maintenance and repair of threaded metal fittings subject to vibration
• Automotive, transportation, manufacturing, and general industrial assemblies

Compatible Materials:

• Close-fitting metal pipes and fittings, including steel and brass
• Cure speed varies with substrate, temperature, gap, and activator use
• Not normally recommended for plastics, particularly thermoplastics that may stress-crack; confirm compatibility before use
• Do not use in pure oxygen or oxygen-rich systems or as a sealant for chlorine or other strong oxidizing materials

Technical Properties:

• Technology: Acrylic
• Chemical type: Methacrylate ester
• Cure mechanism: Anaerobic; activator may be used as a secondary cure method
• Color / appearance: Purple liquid
• Components: One component; no mixing required
• Viscosity classification: Medium
• Brookfield viscosity at 25°C: 9,000-20,000 mPa·s (cP), RVT spindle 3 at 2.5 rpm
• Specific gravity at 25°C: 1.02
• Flash point: Greater than 93°C (199.4°F), Tagliabue closed cup, per the current SDS
• Boiling point: Greater than 150°C (302°F), per the current SDS
• Breakaway torque after 24 hours at 22°C on M10 steel nuts and bolts: 2 N·m (20 lb·in), ISO 10964
• Compressive shear strength on steel pins and collars: At least 1.5 N/mm² (220 psi), ISO 10123
• Full performance: Allow at least 24 hours for maximum pressure and solvent resistance
• Cold-strength testing: Tested to -75°C (-100°F); performance below that temperature was not tested
• Cured-material testing includes motor oil, unleaded gasoline, brake fluid, ethanol, acetone, water/glycol, E85, B100 biodiesel, and DEF under the specific TDS test conditions
• LOCTITE Material Specification: LMS dated September 1, 1995

Package Information:

• Supplied U.S. SDS reference: Henkel IDH 135486; item number 54531
• Package quantity: 1 container

Directions:

1. Clean all external and internal threaded surfaces with a suitable LOCTITE® cleaning solvent and allow them to dry.
2. For inactive metals or when curing is too slow, apply LOCTITE® Activator 7471™ or 7649™ to all threads and allow it to dry.
3. Apply a continuous 360° bead to the leading male threads, leaving the first thread free. Work the sealant into the threads so it fills the voids.
4. For larger threads or voids, increase the amount and apply a 360° bead to the female threads as well.
5. Assemble and wrench-tighten the fitting according to the fitting manufacturer's recommendations.
6. Properly tightened fittings seal immediately against moderate pressure. Allow at least 24 hours for maximum pressure and solvent resistance.
7. For disassembly, use standard hand tools. If necessary on engagement lengths or diameters over 1 inch, apply localized heat to approximately 250°C (480°F) and disassemble while hot.
8. Remove cured residue using a suitable LOCTITE® solvent and mechanical abrasion such as a wire brush.

Storage:

• Keep the original container tightly closed in a cool, dry, well-ventilated area away from heat, sparks, flame, and incompatible materials.
• SDS safe-storage range: 0°C to 32°C (32°F to 89.6°F).
• TDS optimal storage range: 8°C to 21°C (46°F to 70°F).
• Storage below 8°C or above 28°C (82°F) can adversely affect product properties.
• Do not return unused material to the original container because contamination can affect performance.
• Store locked up as directed by the current SDS.

Safety & Transportation:

• Warning: Causes skin irritation and serious eye irritation; may cause an allergic skin reaction; is suspected of causing cancer; and may damage organs through prolonged or repeated exposure.
• Use with adequate ventilation. Avoid breathing vapor, mist, or spray. Wear chemical-resistant gloves, protective clothing, and eye/face protection; the SDS specifically identifies neoprene gloves.
• U.S. DOT ground: UN 3082, RQ, Environmentally hazardous substance, liquid, n.o.s., Class 9, Packing Group III.
• ICAO/IATA air: UN 3082, RQ, Environmentally hazardous substance, liquid, n.o.s., Class 9, Packing Group III.
• IMO/IMDG water: UN 3082, RQ, Environmentally hazardous substance, liquid, n.o.s., Class 9, Packing Group III.
• The SDS states that its transportation information applies to the formulation itself and is not specific to packaging. Package-size exceptions or special provisions must be confirmed before shipment.
• The supplied SDS does not separately state marine-pollutant status or limited-/excepted-quantity eligibility.
• For complete safety, handling, first-aid, disposal, regulatory, and transportation information, consult the current Safety Data Sheet.