Fasto A765 – High Lubricity Pipe Thread Sealant for Serviceable Joints
Fasto A765 is a single-component, medium-strength, PTFE-based anaerobic pipe sealant formulated for locking and sealing straight and tapered metal pipe threads. It cures in the absence of air when confined between close-fitting metal surfaces, forming a flexible, vibration-resistant, and leak-proof seal.
Its very high viscosity and thixotropic paste consistency, combined with high lubricity, make Fasto A765 ideal for applications requiring easy assembly, controlled torque, and convenient disassembly during servicing.
Fasto A765 provides an almost instant low-pressure seal and, once fully cured, can seal up to the bursting pressure of the pipe (≈10,000 psi).
PTFE-Based Anaerobic Technology Ensures excellent sealing with added lubricity.
Medium Strength – Easy Disassembly
Breakaway torque: 3.5 Nm
Prevailing torque: 1.5 Nm (M10 steel fasteners).
Very High Viscosity, Thixotropic Paste Approx. 300,000 cPs (low shear) – prevents run-off and migration.
Instant Low-Pressure Sealing Seals up to 2 bar within ~20 minutes.
High Final Pressure Resistance Seals up to pipe bursting pressure (~10,000 psi).
Wide Operating Temperature Range -60°C to +150°C (continuous).
Excellent Chemical & Solvent Resistance Resistant to motor oil, petrol, brake fluid, acetone, ethanol, propanol, and water.
White Colour Easy visual identification during application.
Benefits
Prevents leakage and vibration loosening in pipe systems
Enables easy assembly and controlled disassembly
Ideal for maintenance-friendly hydraulic and pneumatic joints
Provides long-term sealing reliability
Suitable for medium to coarse pitch pipe threads
Primary Application
Sub-Applications
Functional Purpose
Key Performance Advantage
Pipe Thread Sealing & Locking
Straight & tapered metal pipe threads
Prevent leakage and loosening of pipe joints
PTFE-based sealing with controlled locking
Medium to Coarse Pitch Pipe Threads
Ø15 mm to Ø80 mm pipe threads
Reliable sealing on larger thread profiles
High viscosity, excellent gap filling
Hydraulic & Pneumatic Line Sealing
Hydraulic fittings, pneumatic joints
Leak prevention under pressure
Instant low-pressure seal, high final pressure resistance
Vibration-Exposed Pipe Systems
Pumps, compressors, machinery piping
Maintain seal integrity under vibration
Prevents vibration loosening
Serviceable Pipe Assemblies
Pipe joints requiring future maintenance
Enables disassembly without damage
Low strength break & prevail torque
Industrial Fluid & Gas Systems
Oil, fuel, water & process lines
Long-term sealing & corrosion protection
Excellent chemical & solvent resistance
General Industrial Pipe Sealing
Utility piping, process installations
Clean, non-fouling sealing
Does not cure outside the joint
Surface Preparation
Ensure threads are clean, dry, and free from grease, oil, and contaminants.
Trials are recommended to determine if additional cleaning is required.
Application Method
Apply Fasto A765 to all engaged threads. To minimize excess sealant inside the joint, apply mainly to the male threads, leaving the first two threads clear.
Assemble the joint and tighten as required.
Allow curing under anaerobic (air-excluded) conditions.
Wipe off excess sealant from the outside of the joint.
Curing Guidelines
Fixture time: 15–25 minutes
Functional cure: 3–5 hours
Full cure: 24 hours
Maximum recommended gap: 0.50 mm
Pipe size range: Ø15 mm to Ø80 mm
Additional Notes
Cure speed depends on temperature, bond gap, and substrate.
On inert metals or at temperatures below 5°C, use Fasto AP49 Activator to accelerate curing (activator may reduce final strength by up to 30%).
Anaerobic sealants are not recommended for pure oxygen or chlorine lines.
Not recommended for certain plastics due to potential stress cracking.
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