Loctite® 272 High Strength Threadlocker

Loctite 272 high-strength threadlocker: high strength and high temperature

Loctite 272 is a high-strength threadlocker designed for threaded assemblies subject to extreme stress. It permanently locks threads exposed to high vibration and elevated temperatures.

Its formula is resistant up to 200 °C continuously, making it the ideal choice for engines, turbines, and critical industrial equipment.

Once cured, disassembly requires impact tools: this guarantees an assembly that will not move, even in the most hostile environments.

What is Loctite 272 and what is it used for?

Loctite 272 is a liquid anaerobic high-strength threadlocker, formulated for threaded assemblies subject to severe conditions: high vibration, repeated shocks, and high temperatures up to 230 °C continuously.

It comes in the form of a red liquid, applicable directly to the threads before tightening. It is suitable for screws, bolts, and studs ranging from M6 to M20 in diameter.

Its typical applications include:

• Engines and thermal equipment exposed to heat
• Industrial machinery assemblies subject to vibration
• Fasteners on compressors, turbines, and pumps
• Bolting in petrochemical or high-temperature environments

How an anaerobic threadlocker works

The term anaerobic means that the product cures in the absence of air. As long as the bottle is open, the liquid remains fluid. Once applied between the threads and the bolt is tightened, oxygen is excluded: curing begins.

The cured product forms a rigid resin that fills the micro-gaps between the threads. Result: the bond resists spontaneous loosening, vibration, and thermal expansion.

Disassembly remains possible with impact tools or after localized heating beyond 230 °C, which distinguishes Loctite 272 from a permanent irreversible bond.

Technical specifications of Loctite 272

Loctite 272 is a high-strength liquid threadlocker, formulated for threaded fasteners exposed to extreme conditions. It comes as a viscous, red, single-component liquid that cures in the absence of air upon contact with metal ions.

Resistance to temperature and mechanical stress

This is the product's strong point: Loctite 272 withstands temperatures up to 200 °C continuously, with acceptable peaks up to 230 °C. It thus outperforms Loctite 243 or Loctite 270, which remain limited to 150 °C.

Mechanically, it develops a breakaway torque of approximately 27 N·m on M10 steel screws. Disassembly remains possible with standard tools but requires significant effort.

• Recommended thread diameter: M6 to M20
• Fixture time: 10 minutes
• Full strength reached: 24 hours
• Chemical resistance: oils, fuels, hydraulic fluids
• Compatible substrates: steel, stainless steel, cast iron, brass

Product	Strength	Max Temp.	Thread diameter	Typical usage
Loctite 272	High	200 °C	M6, M20	Engines, exhausts, high-temperature equipment
Loctite 243	Medium	150 °C	M6, M20	General use, routine maintenance
Loctite 270	High	150 °C	M6, M20	Permanent fasteners, standard temperature
Loctite 648	Very high	175 °C	Up to M10	Cylindrical assemblies, not for standard threads

Loctite 272 vs. other products: which high-strength threadlocker to choose?

The market for high-strength threadlockers offers several similar products. Here is how Loctite 272 compares to its direct competitors.

Comparison table: Loctite 272, 271, 277 and alternatives

Product	Manufacturer	Strength	Max temperature	Viscosity	Typical usage
Loctite 272	Henkel	High	200 °C	Medium	Fasteners exposed to heat, engines, exhausts
Loctite 271	Henkel	High	150 °C	Low	Standard high-strength bolting, small threads
Loctite 277	Henkel	High	150 °C	High	Large diameters, wide threads
Loctite 243	Henkel	Medium	150 °C	Medium	General use, periodic disassembly required
Permabond A131	Permabond	High	150 °C	Low	Generic high-strength alternative
Delo ML 5248	Delo	High	180 °C	Medium	Heavy industry, vibrating environments

Loctite 272 stands out clearly due to its temperature resistance: 200 °C compared to 150 °C for the 271 or 277. This is its main advantage.

271 remains the standard choice when heat is not a factor. Its low viscosity makes it more suitable for small threads (M6 to M20).

277 takes over for large diameters thanks to its high viscosity, but without higher thermal tolerance than the 271.

To summarize: if your application involves heat, vibration, and difficult disassembly, Loctite 272 is the right choice. For a standard application without thermal constraints, 271 is sufficient.

Applications and fields of use for Loctite 272

Loctite 272 is designed for threaded assemblies subject to high mechanical and thermal stress. It is suitable for threads with a diameter of M6 to M20, on ferrous and non-ferrous metals.

Its formula is resistant continuously up to 180 °C, with acceptable peaks up to 220 °C. It is the natural choice for hot environments where a standard threadlocker would fail.

Here are the typical applications where Loctite 272 excels:

• Bolting on combustion engines and gearboxes
• Fasteners on exhaust manifolds and turbos
• Assemblies on industrial compressors and high-pressure pumps
• Screws on industrial ovens and heat treatment equipment
• Heavy maintenance in steel, petrochemical, and cement industries

The product cures by anaerobic action: it hardens in the absence of air, between the threads, without overflowing or dripping. No heat required for application.

Product	Strength	Max Temp. (continuous)	Recommended diameter	Typical usage
Loctite 272	High	180 °C	M6, M20	Engines, exhausts, high-temperature industry
Loctite 243	Medium	150 °C	M6, M20	General use, routine maintenance
Loctite 270	High	150 °C	M6, M20	Permanent assemblies, standard temperature
Loctite 2701	Very high	150 °C	M6, M36	Large threads, demanding permanent assemblies

When the temperature exceeds the capabilities of a standard threadlocker, Loctite 272 remains the benchmark for securing assemblies without compromise.

Application tips and safety precautions

Before any application, thoroughly degrease surfaces with a suitable cleaner (acetone, Loctite 7063...). Any trace of oil or contamination reduces adhesion and compromises the hold.

Apply the product directly to the male thread, on the first 3 to 4 threads. One drop is enough: no need to use too much, as the excess will push out during assembly and does not strengthen the fastening.

Loctite 272 is formulated for temperatures up to 200 °C continuously. It is suitable for screws, bolts, and large-diameter studs (M20 to M36) subject to high vibration or heat.

Curing begins as soon as the two metal parts are in contact, in the absence of air. Allow about 24 hours for full strength at room temperature.

On passive metals (stainless steel, aluminum, zinc), use Loctite 7649 activator to ensure proper curing.

Safety precautions:

• Avoid contact with eyes and skin, wear nitrile gloves
• Work in a ventilated area
• Store the bottle away from light, between 8 and 21 °C
• Close tightly after use to avoid premature curing

Disassembly requires impact tools or localized heating to at least 250 °C. Keep this in mind during design if future disassembly is anticipated.

FAQ - Loctite 272

1. What is Loctite 272 used for?

Loctite 272 is used to lock and seal threaded assemblies subject to high mechanical and thermal stress.

It is particularly suitable for screws, bolts, and large studs (M20 to M36) exposed to temperatures reaching 230 °C continuously, or even 150 °C at peak.

It is typically found in engines, turbines, heavy industrial equipment, and exhaust systems.

2. What is the purpose of Loctite 272?

It serves to prevent the involuntary loosening of threaded fasteners caused by vibration, shock, or repeated thermal cycles.

The product fills the gaps between threads, eliminates contact corrosion, and ensures partial sealing against fluids and moisture.

It is a preferred choice for demanding industrial environments where the failure of an assembly can have serious consequences.

3. Which is the strongest Loctite threadlocker?

Loctite 272 is one of the strongest threadlockers in the Loctite range, with high breakaway strength and above-average thermal resistance.

Loctite 277 offers slightly higher mechanical strength on large thread sizes, but its temperature resistance is lower.

For applications combining high mechanical load and high temperature, 272 remains the essential benchmark in the range.

4. What is the difference between Loctite 272 and Loctite 277?

Both products are high-strength threadlockers, but they do not target exactly the same applications.

Feature	Loctite 272	Loctite 277
Mechanical strength	High	Very high
Temperature resistance	Up to 230 °C	Up to 150 °C
Recommended thread size	M20 to M36	M20 to M36
Color	Red	Red
Typical application	Engines, turbines, exhausts	Heavy assemblies at low temperature

In summary: choose Loctite 272 if your assembly is exposed to high temperatures. Opt for 277 if the stress is primarily mechanical, in a thermally moderate environment.