Fasto A172 – High-Viscosity Threadlocker for Extreme Temperature Applications
Fasto A172 is a high-strength, high-viscosity anaerobic threadlocking compound formulated for locking and sealing metric and imperial threaded fasteners operating under high temperature and vibration conditions. It cures in the absence of air when confined between close-fitting metal surfaces, creating a durable, vibration-resistant, and leak-proof bond.
Its thixotropic, non-drip formulation prevents run-off, dripping, or migration after assembly, making it ideal for vertical and overhead applications where controlled placement is critical.
Very High Viscosity (Thixotropic) Approx. 23,000 cPs – excellent for gap control and vertical use
High Temperature Resistance Continuous service from -50°C to +230°C
Fast Initial Strength Build-Up Fixture time: 4–15 minutes
Good Gap Filling Capability Effective up to 0.30 mm
Excellent Chemical & Solvent Resistance Resistant to motor oil, petrol, brake fluid, acetone, ethanol, propanol, and water
Corrosion Protection Prevents rust and fretting of assembled fasteners
Red Colour Easy identification of high-temperature grade
Benefits
Prevents loosening under vibration and thermal cycling
Ensures leak-free threaded assemblies
Suitable for high-temperature industrial environments
Reduces maintenance, downtime, and re-tightening
Ideal for heavy engineering and automotive applications
Primary Application
Sub-Applications
Functional Purpose
Key Performance Advantage
High-Temperature Thread Locking
Fasteners exposed to elevated operating temperatures
Prevent loosening and leakage under heat
Continuous service up to very high temperatures
High-Strength Permanent Fastener Locking
Medium to coarse threaded screws, nuts & bolts
Secure fasteners permanently
High breakaway & prevailing torque
Large Bolt & Stud Locking
Studs, large-diameter bolts
Maintain joint integrity under load
High viscosity, excellent gap-filling
Heavy Industrial Machinery Assemblies
Industrial equipment, power & process machinery
Prevent vibration-induced loosening
High vibration & shock resistance
Corrosion Protection of Threads
Outdoor and harsh-environment fasteners
Protect threads from corrosion
Seals threads against moisture & contaminants
Leak Prevention in Threaded Joints
Threaded joints exposed to oils & fluids
Seal micro-gaps in threads
Anaerobic curing forms integral seal
High-Viscosity Threadlocking Applications
Vertical or overhead assemblies
Prevent run-off or migration
Thixotropic, stays in place during assembly
Surface Preparation
Ensure threads are clean, dry, and free from oil, grease, and contaminants.
Proper cleaning ensures maximum bond strength and consistent curing.
Application Method
Apply Fasto A172 to all engaged threads.
Assemble the fastener and tighten as required.
Allow curing under anaerobic (air-excluded) conditions.
Wipe off excess adhesive from outside the joint.
Curing Guidelines
Fixture time: 4–15 minutes
Strength build-up:
~15% strength in 10 minutes
~50% strength in 1 hour
100% strength in 24 hours
Full cure: 24 hours
Maximum recommended gap: 0.30 mm
Additional Notes
Cure speed depends on temperature, bond gap, and substrate.
On inert metals (stainless steel, aluminium) or at temperatures below 5°C, use Fasto AP49 or AP69 Activator to accelerate cure (note: activator may reduce final strength by up to 30%).
Anaerobic adhesives are not recommended for pure oxygen or chlorine systems.
Not recommended for certain plastics due to possible stress cracking.
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