Loctite Threadlocker Red 271 Review (2026)
By Nate Sawyer, Editor · Updated July 2026
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- Permanent locking
- Structural bolts
- High vibration
- Heavy machinery
The permanent threadlocker for bolts that must never back out. It roughly doubles the holding torque of blue, so it belongs on structural and safety-critical fasteners, with the tradeoff that you'll need a torch to ever take them apart.
Pros
- Roughly double blue 242's breakaway torque for a truly permanent, vibration-proof lock
- Ideal for safety-critical and high-vibration bolts like suspension, frames, and machinery
- Seals threads against leaks and corrosion just like the medium-strength version
Cons
- Removal requires localized heat (~500F) plus heavy torque, so no easy servicing
- Overkill and frustrating on any fastener you'll want to remove routinely
- Anaerobic cure still needs bare metal-to-metal contact to set properly
Specifications
| Type | High-strength anaerobic threadlocker |
|---|---|
| Set time | Fixture ~1 hr on steel |
| Full cure | 24 hr |
| Bonds | Metal threaded fasteners up to 1 in (M25) |
| Strength | High; ~230 in-lb breakaway on 3/8-16, needs heat (~500F) to remove |
| Temp range | Up to 300F (149C) |
Frequently Asked Questions
- How do you remove a bolt secured with red 271?
- Localized heat of about 500F plus heavy torque. There is no hand-tool shortcut, which is exactly the point of a high-strength threadlocker — and exactly why it is the wrong choice on anything you service routinely.
- What size fasteners does red 271 cover?
- Metal threaded fasteners up to 1 inch (M25), with roughly 230 in-lb breakaway on a 3/8-16 bolt. It fixtures in about an hour on steel and fully cures at 24 hours, rated to 300F.
- Will red threadlocker set on plastic threads?
- No. It is anaerobic, meaning it cures in the absence of air and in contact with bare metal. On plastic threads it simply never hardens.