Loctite 243 Vs. 242 – Is There Any Difference Between Them?

Thread lockers are one of the most commonly used adhesives in the mechanical industry. The property of the adhesive allows for a stronger hold between the metal parts.

Both the Loctite 242 and 243 are thread lockers. This is why they're one of the most wanted adhesives amongst mechanics. Once applied, it's very hard to break the bond that they create.

Both of these products have very good reviews. So what is the difference between Loctite 242 vs 243? Which one should you choose for what kind of project? Let's find out in detail.

About Loctite 242

Loctite 242

Loctite threadlocker 242 was created for ceiling and locking threaded fasteners. This adhesive can be used on any hard surfaces. It cures completely in the absence of air.

The adhesive can create a strong bond and is usually used in the mechanical industry.

Benefits Of Using Loctite 242

We've seen a lot of mechanics use the Loctite 242. Here are the benefits that this adhesive offers.

Protecting Threads

A lot of thread lockers often damage the threads significantly. But the Loctite 242 does not. In reality, the adhesive is actually capable of protecting the threads!

Prevents Loosening Of Fasteners

Once applied, this adhesive can absorb the shock caused by vibrations. This results in longer lasting metal fasteners.

Can Be Removed

If you have made a mistake, or need to remove the thread locker, you can easily do so by using some hand tools.

You might have to apply a little bit of pressure, but it will eventually come off.

Disadvantages Of Using Loctite 242

There is only one significant disadvantage of using Loctite 242. And here it is-

Low Oil Resistance

Loctite 242 can keep your threads in perfect condition, but it does not have a very high oil resistance. This is a massive disadvantage, as the adhesive is used in mechanical parts which are often in contact with lubricants and oils.

About Loctite 243

Loctite 243 is an upgraded version of the 242. In the initial application, you might not notice any significant difference between the two products. But in reality, there lies a huge difference in their tolerance to oil.

Advantages Of Using Loctite 243

Now, here are the advantages that you get from using the improved version, Loctite 243.

It’s A Sealant

This adhesive, not only works as a thread protector but also creates a seal against any leakage.

No Vibrations

Once applied, the adhesive will stop the vibrations of the nuts. This prevents the loosening of the metal parts. By absorbing all the shock, the adhesive can keep mechanical parts in better health for a longer time.

No Thread Corrosion

The improved Loctite 243 is capable of adding protection against corrosion. If you want the right protectant for your thread, the Loctite 243 is the adhesive you need.

Disadvantages Of Using Loctite 243

There are not a lot of disadvantages to using Loctite 243. But there is one thing that we would like to mention.

Hard To Dismantle

If you need to remove the Loctite 243, you will have to go through a little bit of hassle. This adhesive is very strong. Sometimes, using just hand tools might not be able to take it off completely. In situations such as this, you will need to use a blowtorch or a propane gun.

Comparing Loctite 243 Vs 242 | Know The Differences

difference between Loctite 243 and 242

If you ask a professional, most will tell you to buy the Loctite 243 instead of the 242. But why so? What is so different and what is so better about the 243 version? Let's see here.


Both the Loctite 243 and 242 are medium strength thread locking adhesives.

The Loctite 243 is often used to secure and seal metal nuts and bolts. Mechanics use this form of adhesive to tone down shock and vibration.

Loctite 242 is often used for ceiling threaded fasteners.


One of the main features that an adhesive should have is strength.

When compared, the Loctite 243 is a tad bit stronger than the 242. The difference is not a deal breaker, but it is noticeable.

Both of these adhesives have the capability to create an incredibly strong bond between metals, but the 243 does a slightly better job.

Oil Resistance

As we've mentioned before, one of the main differences between the Loctite 243 and 242 is that it is more oil resistant than 242.

Because this form of adhesive is widely popular in the mechanic sector, having oil resistance is a must.

That is why a lot of mechanics will say that the Loctite 243 performs better than the Loctite 242.

Low Maintenance

Loctite 243 is oil resistant. This means that the adhesive can be added to threads without needing to give it a thorough cleaning.

The adhesive will still stick properly even if there is a little bit of dust or oil on your threads. On the other hand, when using Loctite 242, you need to ensure that the surface is squeaky clean.

Frequently Asked Questions

1. How To Remove Loctite 243?

If you have added Loctite 243 to a bolt, but need to remove it now, you can do so by using some hand tools.

If the hand tools are not able to remove the nut, You can use the help of a butane or propane torch. With an evenly applied heat, the adhesive will melt and let loose.

2. How Long Does Loctite 243 Take To Cure?

Loctite 243 will start to dry very quickly after application. But, you need to let the adhesive cure for a minimum of 24 hours before use.

This is also the same for Loctite 242.

3. Is Loctite Waterproof?

Loctite adhesives are mostly waterproof. The Loctite 242 and 243 kinds surely are.

Even the clear silicone multi-purpose adhesives are also waterproof and can be used to create a protective seal between rubber, tile, porcelain, metal, and glass.

4. What Color Is Loctite 243?

Loctite 243 comes in blue color. So does Loctite 242. But, if you search the internet, you can sometimes come across clear ones as well.

5. How Long Can You Store Loctite 243 And 242?

You can store and open bottles of Loctite 243 and 242 for at least 12 months. After that, the adhesive will start to cure inside the bottle.

If you can store the bottles in a cool environment, with no exposure to air, it might last a little bit longer.

Final Words

Both the Loctite 242 and 243 are great adhesives for mechanical use. But, they do have their differences.

When it comes to Loctite 242 vs. 243, we would suggest you choose the latter one. This is because the Loctite 243 is an improved version of the previous Loctite 242.

Not only is the Loctite 243 a lot stronger, but it also has very high oil resistance. Given that this adhesive is mostly used in mechanical industries, this is a huge advantage!

Up Next: Know the difference between krazy glue & gorilla gule.


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