If you've ever had a bolt mysteriously come loose over time—or worse, fall out completely—threadlocker is your new best friend. These liquid adhesives are designed to keep threaded fasteners from loosening due to vibration or thermal expansion.
Threadlockers are a must-have in both automotive and general DIY applications. But not all threadlockers are the same. The two most common types—red and blue—have very different strengths and removal methods. Here's how to choose the right one for your project.
What Is Threadlocker?
Threadlocker is a liquid adhesive that hardens in the absence of air when applied between two metal surfaces. Once cured, it helps prevent fasteners from vibrating loose or corroding over time.
Most formulas are anaerobic and available in different strengths (low, medium, and high). Red and blue are the most widely used in garage and shop settings.
Blue Threadlocker: Removable and Reliable
Blue threadlocker is considered medium strength. It’s ideal for fasteners that need to stay put but may require future disassembly with hand tools.
Use blue threadlocker on:
- Valve cover bolts
- Water pump bolts
- Drive shaft bolts
- General automotive hardware
It’s easy to apply and typically cures in 10–20 minutes with full strength reached in 24 hours.
Red Threadlocker: High Strength, Permanent Bond
Red threadlocker is high strength and intended for fasteners that you don’t plan to remove regularly—or ever. It’s used in heavy-duty applications where vibration is extreme and bolt failure isn’t an option.
Use red threadlocker on:
- Engine mount bolts
-
Suspension bolts
- Transmission components
To remove fasteners with red threadlocker, you’ll typically need heat (about 500°F) and hand tools.
Application Tips for Best Results
- Clean threads with brake cleaner or degreaser before applying
- Apply threadlocker to the bolt threads (not the hole)
- Avoid over-torquing once applied
- Allow full cure time before exposing to stress or load
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Store in a cool, dry place with the cap tightly sealed
Final Thoughts
Threadlockers are a simple, inexpensive way to improve the safety and reliability of your builds. Whether you're rebuilding a suspension or assembling a tool cart, the right formula ensures your work stays tight and secure.
Explore threadlocking solutions and adhesives from OneSource Supply Co.: https://onesourcesupplyco.com/products/sealants-adhesives-rtv-silicones-epoxies-lubricants-anaerobics-cyanoacrylates-12
