Loctite Threadlocker 277 Red High-Strength Liquid 50 mL — Permanent for up to 1½" Bolts

Loctite 277 is a red, high-strength liquid threadlocker formulated to permanently secure large bolts and studs up to 1½" (38 mm) while resisting vibration, corrosion, and loosening.

Designed for industrial and heavy-duty applications, this 50 mL bottle of Loctite 277 delivers a permanent, pressure-activated adhesive that fills gaps between threads and cures to a tough polymer. It bonds quickly at room temperature, protects fasteners from rust and environmental damage, and remains serviceable with heat and mechanical removal methods. Manufactured in the United States, this product is intended for use on metal fasteners where a long-term, heavy-duty locking solution is required.

How does Loctite 277 secure large bolts and studs?

Loctite 277 is a liquid anaerobic adhesive that hardens when confined between metal threads in the absence of air. It locks mating parts by polymerizing into a durable network that resists shear and vibrational loosening, giving a strong mechanical bond across the threaded joint.

• High-strength formulation for permanent locking on heavy fasteners
• Effective on bolt diameters up to 1½" (38 mm)
• Works with standard ferrous and non-ferrous metal threads

What are the protection and durability benefits?

Beyond securing fasteners, the cured adhesive forms a seal that inhibits moisture and contaminants from reaching the thread interface. This barrier reduces the risk of corrosion and fretting, extending the service life of assemblies exposed to harsh environments.

• Seals threads against rust and environmental ingress
• Maintains clamp load under vibration and thermal cycling
• Long-term performance suitable for heavy equipment and structural connections

Can Loctite 277 be removed or serviced later?

Though formulated for high-strength, permanent locking, Loctite 277 can be disassembled using heat and appropriate tools. Heat application softens the cured polymer, allowing removal with wrenches, extractors, or by drilling when necessary for repair or replacement.

• Removable with localized heat (typically applied with a torch or heat gun)
• Mechanical methods such as impact tools or drilling assist extraction
• Plan for service access if future disassembly is anticipated

What practical tips improve application success?

Proper surface prep and correct application amount ensure reliable curing and maximum bond strength. Clean threads of oil, grease, and debris, apply a moderate bead, and assemble to recommended torque to achieve optimal performance.

• Clean fastener threads with a solvent or degreaser before applying
• Apply sufficient threadlocker to coat mating threads—avoid excess pooling
• Allow cure time under typical ambient conditions for full strength

Who is this for? Loctite 277 is intended for technicians, maintenance crews, fabricators, and engineers who need a dependable, high-strength threadlocking solution for large-diameter bolts and studs in automotive, industrial machinery, construction, or heavy equipment. Choose this product when you require a permanent lock with corrosion protection and the option to remove fasteners with controlled heat and tools.