Loctite 277 Threadlocker(bottle)

LOCTITE 277 is a premium high-strength, anaerobic threadlocking adhesive designed for the permanent locking and sealing of large threaded fasteners, typically M25 and above. This red, UV-fluorescing acrylic dimethacrylate ester threadlocker cures in the confined, oxygen-free environment between mating metal threads, creating a rigid bond that resists loosening from vibration, shock, and dynamic loading — even in extreme service conditions.

Key Features

A defining feature of LOCTITE 277 is its military and industry qualification: it's tested to the lot requirements of Military Specification Mil-S-46163A and to ASTM D5363 general and detail requirements for North American production. This makes LOCTITE 277 a preferred choice for defense, aerospace-adjacent, and heavy industrial applications requiring documented quality assurance. The one-component formula requires no mixing, has a medium viscosity (6,000–8,000 mPa·s), and fluoresces under UV light for quick post-application inspection — a valuable feature for quality control on production lines.

Performance Data

After 24 hours at 22°C, LOCTITE 277 achieves breakaway and prevail torque values of 32 N·m on M10 steel hardware, with breakloose torque reaching 38 N·m and max prevail torque of 40 N·m when pre-torqued to 5 N·m. Compressive shear strength on steel pins and collars is ≥9 N/mm². This threadlocker has been cold-tested to -75°C and retains substantial strength through heat aging at 100°C, 120°C, and 150°C across thousands of hours. Chemical resistance testing shows excellent retention of strength in motor oil, unleaded gasoline, brake fluid, acetone, ethanol, and diesel exhaust fluid (AdBlue), making LOCTITE 277 suitable for fluid-exposed automotive and industrial fastener applications.

Applications

LOCTITE 277 threadlocker is used extensively in heavy machinery assembly, automotive and commercial vehicle manufacturing, off-highway equipment, defense and military hardware, and any bolted joint subject to high vibration and load where permanent locking is non-negotiable. It performs reliably across substrate types including steel, brass, zinc dichromate, and stainless steel, with cure speed naturally varying by substrate reactivity.

Directions for Use

Clean and dry all mating surfaces with a LOCTITE cleaning solvent before assembly. For inactive metals or slow cure speeds, apply Activator 7471 or 7649 to the threads and let dry before applying the threadlocker. Dispense several drops onto thru-hole bolt threads at the nut engagement point, or down the threads for blind holes. For thread sealing applications, apply a continuous 360° bead to the leading threads, leaving the first thread free, and assemble normally. Disassembly requires localized heating to approximately 250°C. Cured product is removed via solvent soak combined with mechanical abrasion, such as a wire brush.

Why Buy From Tapemart

As an authorized LOCTITE distributor, Tapemart supplies genuine LOCTITE 277 high-strength threadlocker with verified lot traceability and full technical documentation. Whether you need military-spec threadlocking adhesive for defense contracts or simply want a proven, high-strength solution for critical bolted joints, Tapemart delivers authentic LOCTITE products with the speed and support your operation demands. Order LOCTITE 277 from Tapemart and lock down your most demanding fastener applications with confidence.