Product details
| Grade | Loctite 271 |
| Strength | High strength |
| Colour | Red |
| Family | Threadlockers |
| Brand | Loctite (Henkel) |
| Stock | Held in Dubai — buy one or bulk |
Pack sizes
Prices on request. Tell us the quantity you need.
Check stockWhat Loctite 271 is for
The classic red high-strength grade. Low viscosity, permanent — it locks and seals bolts and studs up to M25 against shock and vibration, and disassembly needs heat. It carries a UL classification for use in devices handling petrol, petroleum oils and natural gas at up to 2 in. pipe size.
Key features
- High strength — permanent, heat needed to disassemble
- Low viscosity, wicks into the thread
- For bolts and studs up to M25
- UL classified (MH8007) for devices handling petrol, petroleum oils and natural gas
- Tested to the lot requirements of Mil-S-46163A (a regional approval)
- Full strength retained in petrol and brake fluid to 1,000 hours
Typical applications
- Studs and bolts
- Heavy machinery
Technical data
Uncured material
| Technology | Acrylic |
| Chemical type | Dimethacrylate ester |
| Appearance | Red liquid |
| Fluorescence | Positive under UV light |
| Components | One component — no mixing |
| Cure | Anaerobic; secondary cure by activator |
| Viscosity, Brookfield RVT 25°C | Spindle 1 at 10 rpm: 400–600 mPa·s |
| Specific gravity at 25°C | 1.1 |
| Viscosity class | Low |
Torque performance
At 22°C, ISO 10964. Steel nuts grade 2, bolts grade 5.
| Fastener and cure | Breakaway N·m (lb·in) | Prevail N·m (lb·in) |
|---|
| 3/8 × 16 steel, after 90 minutes | 8.5–25.4 (75–225) | 16.9–34 (150–300) |
| 3/8 × 16 steel, after 24 hours | 16.9–34 (150–300) | 22.6–40 (200–355) |
| M10 steel, after 24 hours | 17–40 (150–350) | 23–40 (200–350) |
| 3/8 × 16 zinc, after 24 hours | 4.5–14.1 (40–125) | 16.9–34 (150–300) |
| 3/8 × 16 cadmium, after 24 hours | 4.5–14.1 (40–125) | 16.9–34 (150–300) |
Chemical resistance
Breakaway torque as a percentage of initial strength after ageing.
| Environment | °C | 100 h | 500 h | 1,000 h |
|---|
| Motor oil (MIL-L-46152) | 125 | 85% | 85% | 75% |
| Unleaded petrol | 22 | 100% | 100% | 95% |
| Brake fluid | 22 | 100% | 100% | 100% |
| Ethanol | 22 | 95% | 95% | 95% |
| Acetone | 22 | 95% | 95% | 95% |
| Water / glycol 50:50 | 87 | 100% | 85% | 85% |
Heat performance
| Heat ageing data published to | 150°C |
| Hot strength plotted to | 150°C |
| Ignition temperature (UL) | 304°C |
| Flash point in liquid state | None |
How to use it
- Clean all threads, internal and external, with a Loctite cleaning solvent and allow to dry.
- Shake the bottle thoroughly before use.
- Do not let the nozzle touch metal — it makes the product cure in the tip.
- Thru holes: apply several drops onto the bolt at the nut engagement area.
- Blind holes: apply several drops down the internal threads to the bottom of the hole.
- Sealing: apply a 360° bead to the leading male threads, leaving the first thread free, and work it into the thread roots.
- Assemble and tighten to the specified torque within the fixture time.
Handling and storage
- Not recommended for pure oxygen or oxygen-rich systems.
- Not a sealant for chlorine or other strong oxidising materials.
- Not normally recommended on plastics — thermoplastics can stress-crack.
- On passive metals (stainless, aluminium, plated) or below 5°C, use Loctite SF 7471 or SF 7649 activator to bring the cure speed up.
- Store unopened and dry. Henkel gives optimal storage as 8°C to 21°C; outside 8–28°C the product properties can be affected.
- Do not return decanted product to the original container.
- Disassembly: apply localised heat to about 250°C and take the joint apart while hot — hand tools will not release a high-strength grade.
Loctite 271, 270 or 277?
All three are high-strength permanent grades. 271 is the classic red for clean steel threads up to M25. 270 is the newer green chemistry — oil tolerant and cures on stainless, so it is the better choice on contaminated or passive threads. 277 is high viscosity for bolts and studs M25 and above, where a thin grade drains out of the coarse thread.
Always read the current technical and safety data before use —
ask us and we'll send it with your quotation.
