Loose bolts can lead to big problems—from vehicle vibrations to leaking machinery. That’s why threadlocker is a must-have in any serious DIYer or mechanic’s toolkit.
Threadlockers are adhesives that secure threaded fasteners in place, preventing loosening from vibration, thermal expansion, or impact. But not all threadlockers are the same. Choosing the right one depends on how permanent you want the bond to be—and how easy you want it to be to remove later.
What Is Threadlocker and How Does It Work?
Threadlocker is a liquid or gel adhesive that fills the gaps between threads and cures in the absence of air (anaerobically) to lock fasteners in place. It prevents back-off, seals out contaminants, and resists loosening caused by movement or temperature changes.
Once applied to a bolt or screw and tightened, it starts to cure in minutes and fully sets in 24 hours (or faster with primer).
Types of Threadlocker by Strength
Threadlockers come in different grades, usually color-coded to indicate their strength and removability.
1. Red Threadlocker – High Strength (Permanent)
Red threadlocker is designed for heavy-duty applications where fasteners are not meant to be removed frequently—or ever. It requires heat (typically 450°F+) and tools to disassemble.
Best For: Suspension bolts, engine mounts, heavy machinery, structural hardware
Removal: Requires localized heat and hand tools
2. Blue Threadlocker – Medium Strength (Removable)
Blue threadlocker is the most common and versatile grade. It provides a secure hold while still allowing removal with standard hand tools. This is ideal for general-purpose repairs.
Best For: Automotive bolts, tool handles, appliance screws, shop assemblies
Removal: Hand tools, no heat required
3. Green Threadlocker – Low Viscosity, Wicking Grade
Green threadlocker is designed to wick into pre-assembled fasteners. It’s ideal when disassembly isn’t possible, but you still need to lock things in place. It’s often used on electrical terminals or set screws.
Best For: Electrical connectors, small screws, hard-to-reach assemblies
Removal: May require heat or special solvent, depending on the formula
4. Purple Threadlocker – Low Strength (Micro Fasteners)
Less common but useful for delicate applications, purple threadlocker is designed for tiny screws and fasteners that need low breakaway torque.
Best For: Electronics, eyeglasses, tiny machine components
Removal: Easy with hand tools
Key Considerations When Choosing Threadlocker
- Fastener Size: Use high strength for large bolts, low strength for small screws
- Disassembly Needs: If you’ll need to take it apart later, avoid red
- Material Compatibility: Some formulas aren’t ideal for plastics or aluminum
- Temperature Range: High-temp formulations exist for automotive use
Tips for Proper Application
- Clean threads with degreaser or brake cleaner before application
- Apply threadlocker to both male and female threads if possible
- Avoid over-torquing during installation
- Allow full cure time (usually 24 hours) before stressing the joint
- Use primer or accelerator for faster cure when needed
OneSource vs. Loctite and Permatex
Loctite and Permatex are the most widely recognized brands in threadlocking. OneSource Supply Co. offers comparable performance with industrial-grade formulas at a better value. Our threadlockers meet or exceed industry standards for strength, cure time, and temperature resistance.
Whether you need red, blue, or specialty grades, OneSource’s adhesives are trusted in workshops, warehouses, and repair facilities nationwide.
Final Thoughts
Threadlocker is a small investment that prevents big problems. Whether you're locking down a brake caliper bolt or assembling shelving in your garage, using the right grade makes all the difference.
Red for permanent strength. Blue for everyday reliability. Green for hard-to-reach areas. And with OneSource Supply Co., you’ve got industrial-level locking power at your fingertips.
