Loctite Blue Vs. Red – Differences to Know

As a mechanic or workshop owner, you are familiar with the inconvenience of loose screws, nuts, and bolts, which may lead to weak connections and leakages. A foolproof way of dealing with such a problem is using a high-quality threadlocker. Quality is something you will appreciate from the Loctite blue vs. red review.

Loctite is a pioneer and key player in the threadlocker industry and deals with other industrial-grade adhesives. Loctite blue and red are superior thread-locking fluids that vary functionality-wise. We will compare the two products to guide you on the right pick depending on the intended applications.

what is the difference between red and blue loctite

Loctite Blue Vs. Red Comparison

Loctite 1329467 243 Blue...
Loctite 88442 Red 272...
Loctite 1329467 243 Blue...
Loctite 88442 Red 272...
Amazon Prime
Loctite 1329467 243 Blue...
Loctite 1329467 243 Blue...
Amazon Prime
Loctite 88442 Red 272...
Loctite 88442 Red 272...

What Is Loctite Threadlocker?

Loctite threadlocker is one of many products under the Loctite brand, others being surface treatments, adhesives, sealants, silicone, and epoxy. The company has been operational since its inception in 1956, the creation of Vernon Krieble, an American professor.

Krieble founded the Loctite brand as a game-changer in mechanical reliability. The threadlocker achieved reliability by preventing the loosening of mechanical connections through vibrations.

Back to the main question, Loctite threadlocker is a top-grade thread adhesive you apply between two mating threads of nuts, bolts, or screws. Threaded connections tend to become loose over time due to weight, vibration, corrosion, and mechanical wear.

This thread-locking fluid flows smoothly between the threads and cures, forming a solid bond. The strength of the bond depends on the product you opt for: Loctite has many threadlocker grades with varying robustness.

What Are the Different Types of Loctite?

As hinted earlier, Loctite thread-locking adhesives come in various grades to meet different purposes. This part of our discussion looks at the number grades and suitability.

Regarding suitability, the threadlockers have a high heat-withstanding capability. Nonetheless, there are situations where the heat can be too much. Such a situation calls for the Loctite 263, which can withstand extreme environments without loosening its grip.

This brand’s threadlockers meet different application strengths. Here, we have products like the Loctite 222, a low-strength adhesive ideal for connections that will require disassembling in the future. It is compatible with small threads, a maximum size of M12.

For more strength for temporary assemblies, you can opt for the Loctite 243, which works with medium threads of up to M18. On the higher end of the spectrum, we have the Loctite 263, which offers permanent fixtures and prevents loosening due to vibration or weight. It is perfect for large threads, with a maximum size of M20.

Overhead applications need solid adhesives to prevent dripping. Loctite has stick adhesives for such scenarios, like the Loctite 248, which is basically the Loctite 243 in stick form, and the Loctite 268 for high-strength connections.

Application of Threadlocker

Threadlocker application is easy and does not require any complex or mechanical tools. Start by picking the right adhesive for the work at hand and follow the steps below.

Step 1: Surface Prepping

A crucial part of the threadlocker application involves prepping the surfaces you are working on. It is a simple step requiring you to clean the threads. To clean, you will need a solvent-based cleaner to remove the coat of corrosion inhibitor the fasteners may have. If you don’t remove the corrosion inhibitor, it may affect the chemical reaction that converts the adhesive from liquid to solid.

Clean other materials between the threads, like grease, dirt, and metal debris. You can use a parts washer solvent for the best results. Dry the threads after the wash and ensure there is no trace of the cleaning agents.

Step 2: Apply Threadlocker

Loctite thread-locking adhesive comes in a convenient bottle with a dropper tip, which makes application hassle-free. Drop a few dots of the adhesive on the area the two threads join. Don’t use too much threadlocker, as you may have a messy outcome.

Step 3: Attach the Connectors

After application, you can attach the nut to the bolt or screws to the intended spot. Gently turn the nut to spread the adhesive fluid uniformly.

Step 4: Allow the Threadlocker to Cure

Once the connectors are in place, let the thread-locking fluid cure. Curing of Loctite threadlocker is an aerobic reaction and takes roughly 24 hours to fully form into a solid.

Loctite Colors

Loctite colors indicate their strength, which determines their application. The threadlocker has four color grades: purple, green, blue, and red.

Loctite Purple threadlocker, also known as Loctite 222, is a low-strength adhesive. It is among this brand’s best-selling products, possibly due to its flexibility. As it is a low-strength thread-locking fluid, you can easily detach the connectors with pliers or screwdriver.

Loctite Green threadlocker is a wicking-grade adhesive also available in liquid form. You use it for stabilizing preassembled connections, such as electrical connectors.

Loctite blue and red threadlockers are the primary subjects of our discussion, and we will have a separate in-depth look at them.

Loctite Blue

Loctite Blue

Loctite Blue threadlocker is a medium-strength adhesive suitable for temporary fixes that need to be stable before future disassembly. It provides a strong bond between the threads and typically works with medium threads, a maximum size of M18, or 6mm to 20mm fasteners.

Loctite blue works with different kinds of metals, and you can easily detach the connectors with simple tools like screwdrivers, wrenches, or pliers. This threadlocker comes in many forms; for instance, the Loctite blue threadlocker 242 nut/bolt locker is more of a gel.

This threadlocker may also be liquid, stick or paste. The Loctite QuickTape 249 is a thread sealant tape based on acrylic adhesive. The blue threadlocker sets in 10 minutes and takes 24 hours to cure fully. Like most high-quality threadlockers, it acts against rust and corrosion.

Loctite Red

Loctite Red
Image Credit: amazon.com

Loctite Red threadlocker is a high-strength thread-locking product. It is ideal for permanent fixes that won’t need disassembling in the future and offer immense stability against vibrations and extreme conditions like high heat.

This threadlocker is compatible with all metals, including plated surfaces, without requiring primer. It is convenient, as you don’t have to clean the connectors before the threadlocker application. It sets in an hour and will fully cure after 24 hours.

Once cured, this adhesive forms a robust bond. The robustness makes it perfect for large threaded connectors. The Loctite 263 red is ideal for large threads of up to M20. The Loctite 277 high-strength threadlocker for automotive is very resilient and works with thread sizes as big as 1 inch.

Loctite red is available as a liquid and a semisolid anaerobic. While this adhesive intends to offer a permanent bond, you can still disassemble the connections. Disassembly is challenging and requires high localized heat application, roughly 500 degrees Fahrenheit, to break its bonds.

Loctite Blue Vs. Red Differences

Loctite blue and red threadlockers have several contrasting points that we will discuss based on the following facets.

1. Bonding Intensity

The two adhesive materials have varying bonding intensities. Loctite blue is a medium-strength threadlocker, while red is a high-strength utility. While both offer sturdy connections after curing, Loctite red is superior and suitable for permanent applications.

Loctite red vs. blue. vs. purple, how do they fare in sturdiness? Loctite purple is a low-strength adhesive suitable for temporal and small fixtures. You can easily remove Loctite purple, compared to the sturdier blue and red threadlockers.

2. Applications

The strength of these Loctite threadlockers determines their functionality. You use Loctite blue for temporary connections that you intend to dismantle in the future. The high-strength Loctite red is ideal for permanent fixtures where you have no plans of disassembly.

Considering their strength, Loctite blue is more flexible, and you can use it in various settings as you can remove the adhesive when need be. You can use it for automotive and machinery maintenance. On the other hand, you use Loctite red for extreme applications, such as where there is excess heat and vibrations to maintain the stability of the associated systems.

Regarding application, we touch on the Loctite red vs. blue vs. green comparison, where we learn that Loctite Green is a wicking grade perfect for preassembled connectors, where disassembly is not a primary concern.

3. Curing Time

Loctite blue will set in within ten minutes and cure in 24 hours if correctly applied. Loctite red takes longer to set in, an hour but will cure in 24 hours. The setting and curing time vary depending on environmental factors such as heat.

4. Ease of Dismantling

As mentioned earlier, Loctite Blue targets temporary fixtures and is easy to dismantle. You can use regular tools like wrenches and pliers to disassemble the Loctite blue threadlocker-bonded connections.

The contrast is true when working with the more robust Loctite red, built to offer a long-lasting bond. You will need sophisticated tools like a blow torch to provide localized heat and turning tools like a wrench.

5. Cost

The Loctite blue vs. red price comparison reveals the latter to be costlier. Considering its strength and extreme application situations, the steeper price tag is justifiable.

6. Customer Reviews

You can get an idea of how the Loctite threadlockers perform from online reviews. This comment on a Loctite red vs. blue Reddit thread highlights the ease of dismantling Loctite blue.

On the same thread, you may encounter this contribution hinting at how hard it is to remove Loctite red, prompting the use of a blow torch. It is advisable to read customer reviews from various forums to understand the Loctite thread-locking fluids.

Is Red Loctite Better Than Blue?

The Loctite blue vs. red discussion introduces two high-grade threadlockers to us. The key takeaway from this discussion is the contrasting bonding intensities of the red and blue Loctite adhesives, which dictates their respective applications.

Loctite red provides the strongest bond and is suitable for long-lasting applications where you have no plans of disassembling the connectors. Conversely, Loctite blue is a medium-strength adhesive built for temporary connections. You can easily break the bonds of the blue threadlocker.

The best pick between red and blue Loctite depends on the application. For temporary fixtures, go for Loctite blue, and switch to red for permanent fixtures.  


Hi there, I am R. Hasan Tito, a mechanic, and owner of this website. My friend and I created this website to share our knowledge, expertise, and experience with our fellow mechanics' community and car users. I am a specialist and certified automotive mechanic (Both Heavy Commercial and Private Cars). I worked as a Mechanic and Mechanic Supervisor for over fifteen years at Global Rebound Automotive companies - Toyota, TATA, BMW, Nissan, TVs, and Others. Now, I enjoy my new role of leading a team of automotive experts (in their respective fields) and publish new content on a regular basis on my website and social media.

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