Product Overview
LOCTITE 660 is a high-strength, paste-consistency anaerobic retaining compound designed for bonding cylindrical fitting parts—especially when assemblies have worn seats, keyways, splines or shafts with larger clearances. It cures when confined between metal surfaces and air is excluded, forming a durable bond that resists shock, vibration and leakage. The product is ideal for large-gap applications (clearance up to ~0.25 mm–0.50 mm) and enables reuse of components without remachining.
Key Features & Benefits
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Very high viscosity paste – collects in larger clearances and fills worn assemblies.
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Large-gap capability – supports bond gaps up to approx. 0.25 mm to 0.50 mm (0.01″-0.02″) for worn fits.
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High strength – shear strength approx. 23 N/mm² (≈3335 psi) on steel.
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Repair without remachining – ideal for restoring fit on worn shafts, spun bearings and keyways.
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Anaerobic cure – one-component, no mixing required; cures when confined between metal surfaces.
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Wide service temperature – accommodates typical industrial operating ranges (e.g., –55 °C to +150 °C) for this class of product.
Application
Surface Preparation:
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Clean all mating metal surfaces thoroughly. Remove old adhesive, corrosion, oil and debris.
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Use a solvent degreaser if required.
Application:
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For slip-fit assemblies: apply LOCTITE 660 to the leading edge of the shaft and inside bore; assemble with rotation to distribute.
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For press-fit/clearance assemblies: apply a 360° bead or “flood” the gap with adhesive; immediately assemble under press force.
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For worn parts: apply adhesive to bore or shaft, assemble component, hold until initial set. The high-viscosity paste fills larger clearances for reuse without remachining.
Curing / Handling:
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After assembly, allow curing under confinement. Fixture time ~15 minutes on steel; full strength achieved over 24 hours.
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Avoid disturbing the assembly until initial fixture is achieved.
Disassembly / Repair:
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For parts already bonded, apply localized heat (~260 °C / 500 °F) and lever or press out while hot. Mechanised removal may be required, especially for large or heavy assemblies.
Tips & Notes:
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Ensure gap clearance does not exceed recommended maximum for full strength.
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For passive metals (e.g., aluminium, plated surfaces) or low temperature conditions, cure may slow—use activator if needed.
FAQs
Q1: What clearance can LOCTITE 660 handle?
A1: It is designed for clearances up to ~0.25 mm to 0.50 mm (0.01″-0.02″).
Q2: Can it bond worn components without remachining?
A2: Yes — its high-viscosity paste formulation enables bonding of worn parts such as keyways, splines and seats without machining.
Q3: Does it require mixing or activator?
A3: No mixing required — it is a one-part anaerobic adhesive. For passive metals or low temperatures, an activator may expedite cure.
Q4: How do I remove bonded parts?
A4: Apply localized heat (~260 °C), then apply mechanical force to separate. Bonded parts are not intended for easy removal.
