Loctite High-Strength Threadlocker 277 — Red 50 mL, Secures Bolts up to 1½ in, Vibration-Resistant

Loctite 277 is a high-strength red threadlocker designed to permanently secure bolts and fasteners up to 1½ inches, preventing loosening from vibration and protecting threads from corrosion.

Built for mechanics, maintenance technicians, and serious DIYers, Loctite 277 is a single-component anaerobic adhesive formulated to cure in the absence of air when confined between metal surfaces. The 50 mL bottle supplies enough product to treat large bolts and assemblies while its high-strength bond resists heavy vibration and shock. When service is required, the adhesive can be removed using heat and common hand tools, making it suitable for long-term structural and machinery applications.

How does Loctite 277 secure large bolts against vibration?

The formula cures to form a durable thermoset plastic between threads, locking fasteners in place and stopping movement caused by vibration or thermal cycling. It fills gaps to maintain clamp load and reduces the risk of fastener loosening in engines, gearboxes, and industrial equipment.

• Effective on bolts and studs up to 1½" (38 mm) in diameter
• Resistant to vibration, shock, and thermal expansion
• Works on passivated and plated metals

What performance and protective benefits does it provide?

Beyond mechanical locking, Loctite 277 offers corrosion protection by sealing threads and limiting moisture ingress. The cured polymer helps prevent fretting and galvanic corrosion on dissimilar metal assemblies in harsh environments.

• Protects threads from rust and corrosion
• Maintains preload to prevent loosening over time
• Suitable for heavy-duty industrial and automotive applications

How do I apply and remove this high-strength threadlocker safely?

Application is straightforward: clean the mating threads, apply a few drops to the bolt or nut, assemble parts, and allow the adhesive to cure. For removal, apply controlled heat to the fastener to weaken the cured adhesive, then use hand tools to back out the bolt or nut.

• Surface prep: degrease and remove loose debris for best cure
• Cure: anaerobic cure between metal surfaces; fixture times vary by gap and temperature
• Removal: heat and mechanical leverage with appropriate tools

Who is this for? Loctite 277 50 mL is aimed at professionals and advanced hobbyists who need a reliable, long-lasting locking solution for large fasteners—automotive technicians, heavy equipment mechanics, industrial maintenance personnel, and anyone assembling structural components exposed to vibration or corrosive conditions. If you need a dependable high-strength threadlocker that secures bolts up to 1½" and offers corrosion protection while remaining serviceable with heat and tools, this product fits those requirements.