How does threadlocker work? When should it be applied, and how much? In this guide, we’ll answer all your questions about this handy adhesive.
Fasteners such as nuts and bolts can easily become loose or damaged. Over time they may be exposed to vibration, or contact with chemicals or water, which can lead to rust, leaks, or other damage.
Luckily, there’s a solution – threadlocker. But what is it, exactly? And how does threadlocker work on fasteners?
Threadlocker is a high-strength adhesive. It creates a film over the threads of the fastener, essentially locking it in place, and preventing it from loosening. This air-tight adhesive layer also protects the fastener from rust, leaks, and corrosion.
For this reason, threadlockers are used in many industries. They’re often applied to machinery, engines and building structures, as they reduce the need for maintenance, keeping fasteners in good condition for a longer period of time.
While threadlockers have industrial uses, they can also be used for DIY purposes. So, if you’re wondering when to use threadlocker, or which one to choose for your project, consider the following factors.
Vibration – threadlockers offer protection against vibration, but some products are more suitable for heavy vibration.
Strength – consider whether you want permanent adhesion or not. High strength or “permanent” threadlockers are more challenging to remove, while other products can be taken off using ordinary tools.
Temperature – choose a threadlocker that can withstand the temperature conditions for your project.
Loctite threadlockers come in different strengths, which are colour-coded.
For example, blue threadlocker is medium strength. It’s ideal for use on objects such as car parts, bicycles, or motorised garden equipment – items that that require occasional maintenance. Blue threadlocker can be detached using hand tools.
If you need a more permanent fix, however, try red threadlocker. This industrial grade adhesive is suitable for structural bolts or heavy machinery. Because of its high strength, it can only be removed with exposure to extreme heat (see below).
Once you’ve chosen your product, you need to know how much threadlocker to apply and how to do it effectively. The good news is, it’s simple and straightforward and the process is similar for all threadlockers.
This is how to apply Loctite threadlocker:
- Clean the fastener. Remove any oil or dirt from the threads of the nut, screw, or bolt.
- Shake the bottle. Give the threadlocker a quick shake before use.
- Apply the threadlocker
For through holes: Apply a few drops of threadlocker onto the nut engagement area of the bolt.
For blind holes: Apply a few drops of threadlocker to the bottom of the hole, so it coats the internal threads.
For sealing: Apply the threadlocker all around the leading threads of the male fitting (on the outside), leaving the first thread untouched. Make sure the adhesive completely fills the voids. If you’re working with a big thread, use a larger quantity of the adhesive and apply it to the female fitting (on the inside) as well. - Assemble the parts. Then tighten.
- Wait for the threadlocker to cure. Loctite threadlocker sets in 10 minutes and takes about 24 hours to fully cure.
That’s everything you need to know about how to apply threadlocker! Just keep in mind—it’s only suitable for metal nuts and bolts and won’t work on plastic. But what about removal?
For low or medium strength threadlocker, you can simply remove the fastener using ordinary tools.
To remove a fastener that’s been secured with high strength/permanent threadlocker, you’ll need a blowtorch. Heat the fastener for about 5 minutes at a temperature of 230 °C, then remove it using a wrench. Wear safety gloves.