LOCTITE® 277 is a one-component, high-strength red anaerobic threadlocker made for permanent locking and sealing of large metal bolts and studs, especially M25 (25 mm / 1 in.) and larger. It cures when confined between close-fitting metal threads without air, helping prevent loosening and leakage caused by shock and vibration.
Key Benefits
- High-strength, high-torque retention for large threaded fasteners
- High-viscosity liquid stays where it is applied and helps fill threaded engagement areas
- Helps prevent unwanted movement, loosening, leakage, and corrosion
- Fluoresces under UV light to support application inspection
- Single-component formula requires no mixing
- Can be disassembled with localized heat when normal hand tools are insufficient
Recommended Applications
Use for permanent threadlocking and sealing of large metal bolts, studs, and threaded assemblies in industrial machinery, heavy equipment, powertrain and chassis work, maintenance and repair, oil and gas equipment, power-generation equipment, and remanufacturing. Henkel recommends the product for steel, stainless steel, and brass. Passive metals such as stainless steel, aluminum, and plated surfaces may require an activator when cure speed is slow.
Technical Specifications
| Technology | Acrylic; dimethacrylate ester |
|---|---|
| Cure type | Anaerobic; activator may be used as a secondary cure aid |
| Components | One component; no mixing required |
| Appearance | Red liquid; fluorescent under UV light |
| Strength | High strength |
| Viscosity | 6,000–8,000 mPa·s (cP) at 25°C, Brookfield RVT, spindle 4 at 20 rpm |
| Specific gravity | 1.12 at 25°C |
| Fixture time | 30 minutes (manufacturer-listed typical value) |
| Temperature range | -55°C to 150°C (-65°F to 300°F) |
| Breakaway torque | 32 N·m (280 lb-in) on M10 steel nuts and bolts after 24 hours at 22°C, ISO 10964 |
| Prevail torque | 32 N·m (280 lb-in) on M10 steel nuts and bolts after 24 hours at 22°C, ISO 10964 |
| Specification note | Henkel lists MIL-S-46163A Type I Grade L; the TDS states the product is tested to the specification’s lot requirements and notes that this is a regional approval. |
Available Bottle Sizes and Henkel IDH Numbers
- 36 ml bottle — IDH 555353
- 50 ml bottle — IDH 88448
- 250 ml bottle — IDH 88449
Directions for Use
- Clean: Remove oil, grease, and contamination from internal and external threads with a suitable LOCTITE® cleaning solvent, then allow the surfaces to dry.
- Activate when needed: If cure is slow on inactive or passive metals, across larger gaps, or below 5°C (41°F), apply LOCTITE® SF 7471 or SF 7649 activator and allow it to dry.
- Through holes: Apply several drops to the bolt at the nut-engagement area.
- Blind holes: Apply several drops down the internal threads toward the bottom of the hole. Add a small amount to the male threads before assembly.
- Thread sealing: Apply a continuous 360° bead to the leading male threads while leaving the first thread free. Work the product into the threads; for larger threads or voids, also apply it to the female threads.
- Assemble: Install and tighten the fastener to the required torque. When assembling multiple fasteners, complete final tightening within the fixture-time window.
- Disassemble: Try standard hand tools first. If necessary, heat the nut or bolt locally to approximately 250°C (482°F) and disassemble while hot using appropriate tools and precautions.
- Clean up: Remove cured residue using a LOCTITE® solvent soak combined with mechanical abrasion such as a wire brush.
Application note: Do not let the dispensing tip touch metal during application; contact can promote cure and clog the nozzle.
Storage
Keep the unopened container in a dry location. Henkel’s optimal storage range is 8°C to 21°C (46°F to 70°F). Storage below 8°C or above 28°C (82°F) may adversely affect product properties. Do not return dispensed or potentially contaminated material to the original container.
Safety and Use Limitations
- California Proposition 65 warning: Cancer and Reproductive Harm — www.P65Warnings.ca.gov.
- Not recommended for pure-oxygen or oxygen-rich systems, or as a sealant for chlorine or other strong oxidizing materials.
- Not normally recommended for plastics, especially thermoplastics that may stress-crack. Confirm compatibility on the actual substrate before use.
- Localized heat used for disassembly can cause burns and other hazards. Use suitable tools, ventilation, and personal protective equipment.
- Review the current Henkel Safety Data Sheet before handling, and follow all listed health, safety, and PPE requirements.
Weight Disclosure
Henkel does not publish a verified packaged shipping weight for these bottles. Shopify weight entries are calculated net-content mass estimates based on the official specific gravity of 1.12 at 25°C: 40.32 g for 36 ml, 56 g for 50 ml, and 280 g for 250 ml. These values do not include the bottle, cap, label, or shipping packaging and are not measured packaged weights.
Technical values are typical manufacturer data and are not purchase specifications. Confirm suitability with testing under actual service conditions and consult the current TDS and SDS.