Loctite Loctite 277 Red Threadlocking Adhesive

The Loctite 277 threadlocker is engineered for permanent locking and sealing of large‑diameter bolts, studs and critical fasteners in industrial assemblies. With its red, high‑viscosity methacrylate formula, it ensures robust protection against vibration‑induced loosening, micro‑movement and corrosion. Ideal for heavy‑duty metal‑to‑metal applications across automation, machine construction, power transmission and maintenance operations, this product supports long‑term reliability where fastener integrity is paramount.

How It Benefits Users

• Permanent‑grade locking for large threads (> 25 mm / 1″) delivers maximum clamp‑force safety.
• High‑viscosity formula resists leakage, creep and adhesive migration in assemblies.
• Fluorescent indicator enables visual inspection of applied adhesive.
• Withstands operating temperatures from approximately –55 °C to +150 °C (–65 °F to +300 °F).
• Removable when required via localised heat (≈ 250 °C / 482 °F) for serviceability.
• Meets military‑specification MIL‑S‑46163A Type I Grade L and ASTM D5363 Group 2 Class 1 Grade 3, supporting high‑reliability installations.

Designed for Robust, Long‑Term Fastener Integrity

Loctite 277 has been optimised for heavy‑duty mechanical assemblies where unwanted loosening can compromise safety, reliability or uptime. Its anaerobic cure mechanism activates in the absence of air, filling voids between steel threads and forming a rigid polymer that resists shock, vibration and thermal cycling. The high viscosity prevents the adhesive from migrating away from the fastener interface, while the fluorescent marker aids quality assurance inspections.

Application Versatility of the Loctite Red Threadlocking Adhesive

• Securing large bolts and studs in heavy‑industrial machinery, gearboxes and large‑frame assemblies.
• Locking structural fasteners in power‑generation and transmission equipment susceptible to vibration.
• Assembly of large electrical enclosures, switchgear and frames in factory automation settings.
• Preventing loosening of critical fasteners in mining, oil & gas, and marine infrastructure.
• Maintenance of flanged connections, large‑thread mountings and construction‑equipment joints.
• Situations where visual adhesion verification is essential.

For more information please check the datasheets.