Loctite threadlockers - which one is right for the job?

Loctite threadlockers are useful in a wide range of practices, from the repair of basic household appliances to complex automotive maintenance. Loctite threadlockers solve a problem that engineers struggled with for a very long time: vibrational loosening. 

There were other solutions to prevent vibrations from loosening screws and fasteners, but they often presented a whole new set of problems for engineers to deal with. When Loctite entered the scene fifty years ago, they provided a simpler way to lock and seal threaded fasteners. 

By applying a liquid adhesive, engineers had a much easier way of preventing vibrational loosening. What made it even better was the high quality and durability of Loctite threadlockers. They quickly proved themselves to be secure and effective combatants to vibrational loosening. 

Depending on the task at hand, there are four different colours of Loctite threadlocker to choose from: purple, blue, red and green. Getting the right colour threadlocker for the job will deliver better results, so we’re going to explain what each of them is best used for. 

Loctite threadlocker purple - low strength

Loctite threadlocker purple comes in at the lower end of the spectrum and is ideal for fasteners smaller than 6mm. This is perfect for low strength metals like aluminium, and other similar strength metals that might fracture easily. 

This threadlocker can also be used to calibrate screws, gauges and metres. Loctite threadlocker purple has a full cure time of 24 hours and allows for disassembly with hand tools. 

Loctite threadlocker blue - medium strength 

Next, we have Loctite threadlocker blue, a medium strength liquid adhesive suitable for all metal threading. This general-purpose threadlocker is best suited for fasteners up to 20mm. 

Although this is a strong all-rounder, it’s perfect for gearboxes, mounting tools, machine tools, pumps and compressors. Like the Loctite threadlocker purple, this grade allows for disassembly with hand tools and also has a 24 hour full cure time. 

Loctite threadlocker red - high strength 

Loctite threadlocker red is a high strength liquid adhesive that is suitable for all metal fasteners. If you need a threadlocker that’s strong enough to permanently keep fasteners in place, this is the one for you. Loctite red will be able to secure any fastener up to 27mm. This means it’s a strong performer when it comes to heavy equipment, such as motor and pump mounts and suspension bolts.

Loctite threadlocker green - penetrating threadlockers

Finally, we have Loctite threadlocker green, which is slightly different from the other Loctite products we have covered. This threadlocker uses capillary action to penetrate into preassembled fasteners. Loctite threadlocker green has a low viscosity and is thinner and runnier than the usual Loctite threadlockers. 

There is no need for disassembly before applying this adhesive, which means it’s perfect for preassemble fasteners. You can also use it on oil-coated fasteners, instrumentation screws and electrical connectors. This grade of Loctite threadlocker can be used on any fastener up to 14mm. 

Choose the right one for the job 

Now that we’ve covered the four main colours, you should be in a better position to pick the right Loctite threadlocker for the job. You might see numbers being listed next to specific threadlockers, but the colour distinction remains the same with these. Regardless of the colour you go for, all Loctite threadlockers offer excellent performance in the locking and sealing of threaded fasteners. 

If you’re still unsure about the Loctite threadlocker types and which would be the best for your project, feel free to contact us today. We stock a wide range of Loctite threadlockers that are used by amateur DIY enthusiasts and professional engineers alike. We’re more than happy to talk you through the range of products and help you pick the right Loctite threadlocker.