Henkel LOCTITE-661 (250ML-BOTTLE)

Additional Product Information

Overview

LOCTITE 661 is a high-strength anaerobic and UV-curing retaining compound designed for bonding cylindrical metal assemblies. Widely used in aviation maintenance and MRO environments, it provides fast fixture times, excellent chemical resistance, and dependable strength at elevated temperatures. Engineering and maintenance teams rely on it to secure rotating components, reduce vibration-related failures, and restore service quickly during AOG situations.

Key Technical Specs for LOCTITE 661

• Type: Anaerobic & UV-curing retaining compound (urethane methacrylate)
• Size/Volume: Available in multiple industrial pack sizes
• Color: Yellow to dark amber liquid
• Viscosity/Consistency: Low viscosity, approx. 300–600 mPa·s (cP) at 25°C
• Cure/Working Time: UV fixture ≤14 seconds; tack free approx. 45 seconds; full cure within 24 hours at 22°C
• Strength: Compressive shear strength ≥15 N/mm² (≥2,175 psi)
• Service Temperature: High-temperature resistance tested up to 180°C (356°F)
• Typical Uses: Retaining gears, sprockets, rotors, bearings, bushings, and shafts
• Shelf Life: Refer to product packaging and SDS for storage and shelf life details

Approvals & Specifications

• Manufactured by Henkel under strict industrial quality controls
• Tested to ISO 10123 for compressive shear strength
• Batch quality testing available under Loctite Material Specification (LMS)
• Refer to Technical Data Sheet and SDS for compliance and certification details

Typical Aircraft MRO / AOG Applications

• Retaining gears and sprockets on gearbox shafts
• Bonding rotors on electric motor shafts
• Securing bearings, pulleys, and bushings
• Repair and re-assembly of cylindrical metal components
• Preventing fretting, vibration loosening, and wear in rotating assemblies

Compatibility & Safety Notes

• Designed primarily for close-fitting metal surfaces
• Not recommended for plastics due to potential stress cracking
• Not suitable for oxygen-rich or strong oxidizing environments
• Use appropriate PPE when handling adhesives
• Consult Safety Data Sheet (SDS) for full safety guidance

Packaging & Procurement

• Available in a range of industrial packaging sizes
• One-component formula requires no mixing
• Store in unopened containers at 8°C–21°C (46°F–70°F)
• Do not return used product to original container
• Contact sales for stock availability and bulk supply

Why LOCTITE 661 is Chosen for AOG / MRO

• Rapid UV fixture for faster turnaround
• High strength and heat resistance
• Excellent chemical and environmental durability
• Reliable performance in vibration-prone assemblies
• Simple one-component application ideal for field repairs

Practical Suggestions for Your Team (AOG Mindset)

• Stock alongside LOCTITE Activator 7471 or 7649 for faster curing
• Clean surfaces with approved Loctite cleaning solvent before application
• Train technicians on slip, press, and shrink-fit assembly methods
• Keep product stored within recommended temperature range
• Use localized heat (~250°C / 482°F) for disassembly when required

Manufacture / Aviation Spec Codes

• Manufacturer: Henkel
• Product ID: LOCTITE 661
• Technology: Acrylic / Urethane Methacrylate
• Reference Document: Henkel Technical Data Sheet (TDS)

Alternative Names & Descriptions

• Retaining compound for cylindrical assemblies
• High-temperature shaft retaining adhesive
• UV/anaerobic retaining compound
• Gear and rotor retaining adhesive
• Industrial cylindrical bonding compound