Loctite 271 High Strength Threadlocker 50ml

Loctite 271 is a one-component, red, high strength anaerobic threadlocker (dimethacrylate ester). Henkel designs it for the permanent locking and sealing of threaded fasteners.

It is a low viscosity grade intended for large bolts and studs up to M25. An activator can be used as a secondary cure, and the product fluoresces under UV light.

Where this product is used

• Permanent locking and sealing of large bolts and studs up to M25
• Brass and steel fasteners, including stainless steel, per Henkel's product page
• Fasteners in contact with petrol, brake fluid, ethanol or 50/50 water/glycol, using the retained-strength data in the Henkel data sheet
• Threaded fasteners where removal by local heat is acceptable

Features

• High strength, for permanent locking and sealing
• One component, no mixing
• Red, with fluorescence under UV light
• Low viscosity: 400 to 600 mPa·s
• Anaerobic cure, with an activator (SF 7471 or SF 7649) as a secondary cure
• 17 to 40 N·m breakaway torque on M10 steel (24 h at 22 °C)
• Removable with localised heat to about 250 °C

Key specifications

Selecting the right option

For a medium strength grade see Loctite 243 Medium Strength Threadlocker; for medium to high strength see Loctite 262 Acrylic Anaerobic Threadlocker Red 50ml.

For bolts and studs M25 and larger, Henkel's data sheets name that size range for Loctite 277 High Strength Threadlocker 50ml and Loctite 272 High Strength - High Temperature 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 about 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 reports strength at 90 minutes and 24 hours at 22 °C and gives no fixture time.

Henkel states no operating temperature range. Hot strength was tested at 0, 100, 120 and 150 °C, and heat ageing at 100, 120 and 150 °C for up to 5,000 h.

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. Read the safety data sheet before use.

Frequently asked questions

What size thread is Loctite 271 for?

Henkel lists large bolts and studs up to M25.

How strong is Loctite 271?

High strength. Breakaway torque on M10 steel after 24 hours at 22 °C is 17 to 40 N·m, and prevail torque is 23 to 40 N·m (ISO 10964).

How do I remove Loctite 271?

Heat the nut or bolt locally to about 250 °C and disassemble while hot.

What temperature can Loctite 271 handle?

The Henkel data sheet states no operating temperature range. Hot strength was tested at 0, 100, 120 and 150 °C, so check those results against your service temperature.

What fluids does Loctite 271 resist?

After 1,000 hours at 22 °C, Henkel reports retained strength of 95% in gasoline, ethanol and acetone, 100% in brake fluid and 85% in 50/50 water/glycol. In motor oil at 125 °C it retains 75%.

What approvals does Loctite 271 list?

Mil-S-46163A lot requirements (regional approval), ASTM D5363 for North American lots, and UL Classification MH8007 (regional approval) for gasoline, petroleum oils, natural gas to 300 psig, butane and propane, up to 2 in pipe.

Related products

See also: Loctite 243 Medium Strength Threadlocker, Loctite 262 Acrylic Anaerobic Threadlocker Red 50ml, Loctite 263 High Strength Threadlocker, Loctite 277 High Strength Threadlocker 50ml, Loctite 7471 Primer T Surface Preparation Activator Aerosol 133g.