Loctite 277 High Strength Threadlocker 50ml

Loctite 277 is a one-component, red, high strength anaerobic threadlocker (dimethacrylate ester). Henkel designs it for the permanent locking and sealing of threaded fasteners.

The data sheet gives large bolts and studs (M25 and larger) as the typical use. It is a medium viscosity liquid of 6,000 to 8,000 mPa·s, and it fluoresces under UV light for inspection. This listing is the 50 ml pack.

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
• Fasteners where the applied product is checked under UV light
• Assemblies where an activator is used as a secondary cure

Features

• High strength, for permanent locking and sealing
• Medium viscosity, not a high viscosity grade
• One component, no mixing
• Red liquid, fluorescence positive under UV light
• 32 N·m breakaway torque on M10 steel (24 h at 22 °C)
• Tested to the lot requirements of MIL-S-46163A (regional approval)
• Removable with localised heat to about 250 °C

Key specifications

Selecting the right option

The same grade is also sold in the 250 ml pack: Loctite 277 High Strength Threadlocker 250ml.

For a lower strength grade see Loctite 243 Medium Strength Threadlocker; for other high strength grades see Loctite 263 High Strength Threadlocker, Loctite 271 High Strength Threadlocker 50ml and Loctite 272 High Strength - High Temperature Threadlocker 50ml.

Using it

Where an activator is needed, Henkel names Loctite SF 7471 and SF 7649 as the 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; the cure-speed graphs are in the Henkel data sheet. The data sheet gives no fixture time or full-cure time.

The data sheet states no operating temperature range. Cold strength was tested to -75 °C, and it shows hot strength from -50 to 150 °C as a graph only.

Storage and handling

Store unopened in a dry location. Henkel gives 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 stress cracking can occur. Check compatibility with aqueous washing systems. Read the safety data sheet before use.

Frequently asked questions

What size bolts is Loctite 277 for?

The data sheet gives the typical use as locking and sealing large bolts and studs, M25 and larger.

What torque does Loctite 277 hold?

On M10 steel nuts and bolts after 24 hours at 22 °C (ISO 10964), breakaway is 32 N·m and prevail torque is 32 N·m. Pre-torqued to 5 N·m, breakloose is 38 N·m.

How do I remove Loctite 277?

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

Does Loctite 277 fluoresce under UV light?

Yes. Henkel lists fluorescence as positive under UV light.

What operating temperature does Loctite 277 have?

The data sheet states no operating range. It reports cold strength tested to -75 °C and shows hot strength as a graph from -50 to 150 °C.

Is Loctite 277 approved to any standard?

Henkel lists tested to the lot requirements of Mil-S-46163A, which it calls a regional approval, and ASTM D5363 for lots produced in North America.

Related products

See also: Loctite 277 High Strength Threadlocker 250ml, Loctite 272 High Strength - High Temperature Threadlocker 50ml, Loctite 263 High Strength Threadlocker, Loctite 271 High Strength Threadlocker 50ml, Loctite 7471 Primer T Surface Preparation Activator Aerosol 133g.