Loctite 272

Overview

Loctite 272 is a red, high-strength, high-temperature anaerobic threadlocker designed to lock and seal metal fasteners that see both high loads and elevated temperatures. It cures in the absence of air between close-fitting metal surfaces, forming a tough, cross-linked plastic that fills the thread gap.

Once cured, Loctite 272:

• Resists loosening from shock, impact and continuous vibration

• Maintains performance at higher temperatures than standard red grades

• Seals the helical thread path to help prevent fluid/gas leakage and corrosion

It is typically chosen for applications where fasteners are not intended to be removed during normal service and are exposed to hot engines, exhaust regions, heating systems or high-temperature process equipment.

Why choose Loctite 272?

1) High-temperature resistance up to approx. 230 °C
Unlike many standard threadlockers, Loctite 272 is formulated to maintain strength at elevated temperatures, making it suitable for exhaust components, engine housings and hot-end machinery.

2) Permanent-strength locking for critical joints
Loctite 272 provides very high breakaway and prevailing torque on steel fasteners and is intended for joints where unplanned loosening would be unacceptable. Typical examples include heavy-duty pumps, powertrain components and high-temperature flanges.

3) Medium-high viscosity for larger fasteners
With a thicker consistency than some low-viscosity grades, Loctite 272 is well-suited to medium to large bolts and studs, helping it stay on the threads and wet the flanks of coarse or large-pitch fasteners.

4) Locks and seals in one operation
By filling the entire engagement between male and female threads, Loctite 272 locks the fastener against movement and seals the path against leakage, reducing the need for separate mechanical locking devices and thread sealants in many designs.

5) Simple, one-part application and easy inspection
Loctite 272 is supplied as a single-component red liquid in handy bottles. It requires no mixing and is typically fluorescent under UV, allowing quick quality checks to confirm that threadlocker has been applied.

Typical Applications

High-temperature automotive & powertrain

• Exhaust manifold bolts and hot-end engine fasteners

• Turbocharger brackets and high-temperature housings

• Drive and powertrain fasteners near heat sources

Industrial machinery and process equipment

• Bolts and studs on high-temperature pumps, compressors and gearboxes

• Fasteners in ovens, furnaces, dryers and heaters where temperatures are elevated

• Hot flanges and high-temperature pipe supports (for threadlocking, not flange sealing)

General permanent threadlocking in hot environments

• Metal fasteners that see high loads plus elevated temperatures

• Joints where mechanical locking alone is not enough under heat and vibration

Loctite 272 is designed for metal-to-metal threads and is not recommended for plastics or pure oxygen / strong oxidizer service.

How to Use Loctite 272

Step 1 – Surface preparation

• Remove loose rust, dirt and any old threadlocker from the fastener and tapped hole.

• Wipe off heavy oil, grease and anti-seize.

• Light preservative oil films may be tolerated, but cleaner metal surfaces give higher and more consistent strength, especially at high temperatures.

Step 2 – Product application

• Shake the bottle briefly.

• Apply a continuous bead of Loctite 272 to the male threads, covering the full engagement length.

• For blind holes, apply a small amount into the female thread so the adhesive is pushed throughout the engagement as the fastener is installed.

Step 3 – Assembly and tightening

• Assemble the joint and tighten to the specified torque.

• Avoid repeatedly loosening and tightening after the adhesive has started to fixture, as this can disturb the bond line.

Step 4 – Cure and return to service

• Allow the assembly to sit undisturbed until handling strength is reached.

• For maximum performance—particularly in high-temperature and high-load applications—allow up to 24 hours at room temperature before subjecting the joint to full load, pressure or maximum operating temperature.

Step 5 – Disassembly (if ever required)

• It is a high-strength, high-temperature permanent grade.

• For larger fasteners, disassembly usually requires:

  • Localized heating of the joint area (only if compatible with the base materials and design) to significantly soften the adhesive, and

  • High torque with suitable tools to break the bond while the joint is still hot.

Safety & Handling

Typical safety information for high-strength, high-temperature anaerobic threadlockers like Loctite 272 includes:

• Can cause eye and skin irritation, and may cause allergic skin reactions in sensitized individuals.

• Vapours or mists may cause respiratory irritation, particularly in confined spaces.

• Uncured product may be harmful to aquatic organisms if released into the environment.

Basic good practice:

• Use only in well-ventilated areas.

• Avoid contact with skin and eyes; wear safety glasses and suitable protective gloves.

• Wash hands thoroughly after handling and before eating or drinking.

• Do not allow uncured product to enter drains or watercourses.

• Store in the original, tightly closed container, in a cool, dry place out of direct sunlight and away from heat or ignition sources.

Always follow the latest Safety Data Sheet (SDS) for Loctite 272 in your region.

FAQs

Q1: When should I choose Loctite 272 instead of 271 or 263?
Choose Loctite 272 when you need high-strength threadlocking plus elevated temperature resistance—for example, exhaust regions, hot engines or high-temperature machinery. Use 271 or 263 when service temperatures are more moderate and you do not need the extra high-temp capability.

Q2: Is Loctite 272 removable?
Loctite 272 is a high-strength permanent threadlocker. Small fasteners may be removed with strong hand tools, but larger bolts and studs typically require localized heating and high torque for disassembly. If routine removal is expected, a medium-strength grade like 242 or 243 is more suitable.

Q3: What fastener sizes are best for Loctite 272?
Loctite 272 is most often used on medium and larger metal fasteners in high-temperature service—engine bolts, hot-end exhaust fasteners and large bolts on ovens, furnaces and heaters. For very large studs, a heavy-duty, high-viscosity grade like Loctite 277 may be a better match; for small screws, low- or medium-strength grades are easier to remove.

Q4: Can Loctite 272 be used on stainless steel and plated fasteners?
Yes. Loctite 272 can cure on most common metals, including stainless steel and many plated fasteners. Cure is often slower on “passive” metals, so allow extra time before applying full load, or consult Henkel about using an activator if rapid strength build-up is critical.

Q5: Is Loctite 272 oil-tolerant?
Loctite 272 can handle light residues of oil, but heavy coatings of grease, cutting fluid or anti-seize should be removed. For maximum performance—especially at high temperature—threads should be cleaned so that the adhesive can contact bare metal as much as possible.

Q6: Can I use Loctite 272 on plastic threads or mixed metal/plastic joints?
No. Like other anaerobic threadlockers, Loctite 272 is intended for metal-to-metal joints and can cause stress cracking in some plastics. It will also not cure properly on non-metallic threads. For plastic or mixed joints, select an adhesive designed specifically for plastics.

Q7: Does Loctite 272 also act as a sealant?
Yes. Because it fills the gaps between threads, Loctite 272 locks and seals in a single step, helping to prevent leakage of fluids and gases along the thread helix and protecting against corrosion. It does not replace flange gaskets, but it is very effective at sealing through-thread leak paths.