Loctite 277 High Strength Threadlocker 250ml

Loctite 277 is a one-component, red, high strength anaerobic threadlocker (dimethacrylate ester). It is designed for the permanent locking and sealing of threaded fasteners, with large bolts and studs (M25 and larger) as the typical use.

It is classed as medium viscosity, 6,000 to 8,000 mPa·s. It cures in the absence of air between close-fitting metal surfaces, can be given an activator as a secondary cure, and fluoresces under UV light.

Where this product is used

• Permanent locking and sealing of large bolts and studs, M25 and larger
• Threaded fasteners that are not meant for routine removal
• Assemblies exposed to motor oil, petrol or brake fluid
• Larger fasteners where an activator is used to speed the cure

Features

• High strength, for permanent locking and sealing
• Medium viscosity, 6,000 to 8,000 mPa·s
• One component, no mixing
• Red liquid with positive fluorescence under UV light
• 32 N·m breakaway and 32 N·m prevail torque on M10 steel
• At least 9 N/mm² compressive shear on steel pins and collars
• Removable with localised heat to about 250 °C

Key specifications

Choosing the right option

The same grade is also sold in the 50ml pack: Loctite 277 High Strength Threadlocker 50ml.

For a medium strength grade see Loctite 243 Medium Strength Threadlocker; for other high strength grades see Loctite 263 High Strength Threadlocker and Loctite 272 High Strength - High Temperature Threadlocker 50ml.

See also: Loctite 277 High Strength Threadlocker 50ml, Loctite 272 High Strength - High Temperature Threadlocker 50ml, Loctite 263 High Strength Threadlocker, Loctite 271 High Strength Threadlocker 50ml.

Using it

An activator (Loctite SF 7471 or SF 7649) can be used as a secondary cure.

To disassemble, apply localised heat to the nut or bolt to approximately 250 °C and disassemble while hot.

Cure speed depends on the materials, the gap and the temperature.

Cold strength was tested to -75 °C, hot-strength data is a graph from -50 to 150 °C, and heat ageing is graphed at 100, 120 and 150 °C.

Storage and handling

Store unopened in a dry location. Temperature range 8 °C to 21 °C as the optimal range. Storage below 8 °C or above 28 °C can adversely affect the properties of the product.

Limits and safety

Not recommended for pure oxygen or oxygen-rich systems, or as a sealant for chlorine or other strong oxidisers. Not normally recommended for plastics, as thermoplastics can stress-crack. Read the safety data sheet before use.

It reports cold strength tested to -75 °C, and gives hot strength and heat ageing as graphs.