Fasto A777 – Serviceable Pipe Thread Sealing with High Lubricity
Fasto A777 is a single-component, fast-curing, low-medium strength anaerobic pipe sealant formulated to lock and seal medium to coarse 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.
With its medium-viscosity, thixotropic paste consistency and high lubricity, Fasto A777 enables easy assembly, controlled torque, and convenient disassembly, making it ideal for serviceable pipe joints.
Fasto A777 provides an almost instant low-pressure seal and, once fully cured, seals up to the bursting pressure of the pipe, ensuring long-term system reliability.
Fast Curing Anaerobic Technology Fixture time: 4–15 minutes
Medium Viscosity, Thixotropic Paste Approx. 48,000 cPs (low shear) – prevents run-off and migration
High Lubricity Allows easier tightening and servicing
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 -50°C to +150°C (continuous)
Excellent Chemical & Solvent Resistance Resistant to motor oil, petrol, brake fluid, acetone, ethanol, propanol, and water
Fluorescent Yellow Colour Easy visual identification during application
Benefits
Prevents leakage and vibration loosening
Enables easy disassembly and servicing
Ideal for maintenance-friendly pipe systems
Improves long-term sealing reliability
Suitable for pipes Ø15 mm to Ø80 mm
Primary Application
Sub-Applications
Functional Purpose
Key Performance Advantage
Pipe Thread Sealing & Locking
Straight & tapered metal pipe threads
Seal and secure threaded pipe joints
Locks & seals simultaneously
Hydraulic & Pneumatic Line Sealing
Hydraulic fittings, pneumatic connections
Prevent leakage under pressure
Withstands high internal pressure after cure
Gas & Fluid Pipeline Assemblies
Industrial gas lines, fluid transfer pipes
Reliable leak prevention
Anaerobic cure fills thread gaps
Medium to Coarse Pipe Threads
Pipe sizes typically used in industry
Consistent sealing performance
Thixotropic, high-viscosity paste
Serviceable Pipe Joints
Systems requiring maintenance
Allows disassembly when required
Low–medium strength with good lubricity
Vibration-Exposed Pipe Systems
Pumps, compressors, machinery piping
Prevent loosening under vibration
Maintains seal integrity over time
General Industrial Pipe Sealing
Process piping, utility lines
Long-term sealing & corrosion protection
Chemical & solvent resistance
Surface Preparation
Ensure threads are clean, dry, and free from grease or oil.
Trials are recommended to determine if additional cleaning is required.
Application Method
Apply Fasto A777 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: 4–15 minutes
Full cure: 24 hours
Maximum recommended gap: 0.25 mm
Additional Notes
Cure speed depends on temperature, bond gap, and substrate.
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 systems.
Not recommended for certain plastics due to possible stress cracking.
To access Technical & Safety Documents, please submit your details.
