Loctite 242 vs 243 Loctite Threadlocker Comparisons

Last updated on October 18th, 2022 | By: Grady Galvez

When we talk about adhesives, sealants, or surface treatments one name outshines every other brand, and that is Loctite. Now out of all the products of this popular adhesive brand Loctite 242 and 243 are the most sought-after products, although many users spell it wrongly as a lock tight 242. Now a company which is a pioneer in this field and has hundreds of product ranges, to stand out among these products itself speaks volumes about the 242 and 243.

The reason that these two are so popular is because they are known as Threadlockers. It is a type of adhesive which is mostly used by mechanics.

The difference between these two products is difficult to find. The only real difference is that the Loctite 243 is an upgraded version of Loctite 242. There is hardly any difference between the two and when you apply the Loctite 242 or Loctite 243 there is absolute resemblance. The Loctite 243 outperforms Loctite 242 only when it comes to oil tolerance, which is better in Loctite 243.

But as for a genuine advice it is always better to choose the Loctite 243 over Loctite 242 and here are the reasons for that:

Why Is Loctite 243 Is Strongest Loctite Than 242?

As for the fact even the company says the Loctite 243 is an upgraded version of Loctite 242. But people who have been using the Loctite 242 for long are loyal to that and don’t want to go for an upgrade. Their logic is simple and true, that when they are getting great results, are happy with the product and have spent money on it, then why change it?

But the fact of the matter is that the Loctite 243 is really great and would be the best choice to switch to it in the long run.

But yes the products are similar and if you are getting a better deal, then there is not harm to it. Here are the two of them explained in details and also the reasons why Loctite 243 is a better option:

  • It is stronger: We would recommend that you use both products and see for yourself. Any expert who has used both would easily tell you that Loctite 243 is stronger than Loctite 242.

  • It is resistant to oil: This reason alone is enough to prove the Loctite 243’s superiority. The company after hearing the drawbacks from the consumers, improvised on Loctite 242 and came up with Loctite 243 which can be easily used with threads.

  • It’s a boon for lazy people: The Loctite 242 needs you to clean each and every thread before applying the thread locker, which is very time consuming and frustrating. This problem is solved with Loctite 243 as it is oil resistant, so you don’t have to clean it and also it does not matter if there is oil in the threads.

blue loctite

These are the points that make the 243 a better option than the 242. Added to this fact is another reason that the cost difference is also not much, so why not choose the better one.

They both are in fact good for medium-strength applications, which use thread locking like:

  • Rocker Studs

  • Hand Tools

  • Oil Pans

  • Lock Nuts

  • Valve Cover Bolts

  • Disc Brake Calipers

  • Pulley Assemblies

  • Lock Washers

  • Carburetor Studs

loctite threadlocker

The Other Loctite Locker Threads Which Are Also Good And Recommended

Although there are tons of Loctite products in the market, the threadlockers continue to the most popular choice of them all. So here are some good threadlockers by Loctite.

Loctite 222 And 221 – Low Strength

loctite blue

Some Salient Features Low Strength Loctite 221 And 222:

  • Prevents vibration and thus loosening of small fasteners and screws

  • Non-corrosive formula thread locker

  • Can be removed with hand tools with ease

  • Works with ¼ and under small screws and also threaded fasteners

  • Can handle temperatures up to 300°F

  • Fast set time of 10 min and less

It is for people who are looking for a low strength threadlocker. These can be used for small threads which are to the size of M12. They are pretty thin and have low viscosity, which makes it the best choice for threadlocker which are designed for small threads.

Loctite 278 and 272- Temperature Resistant

loctite 270 vs 243

Some Salient Features of Loctite 272 and 278:

  • Fastener size.

  • 1 ½ to 3/8 inches.

  • Can take up to 450°F of heat.

  • The fixture time is between 40 min to 1 hour.

  • Can be easily used on shock bolts, crankshafts, ring gear, and idler bearings.

If you are searching for something that can take on heat and also has medium viscosity then this is the product for you. It can be easily used in high strength applications. It is also designed for permanent thread locking.

Loctite 276 and 270 – High Strength

loctite threadlocker blue

Some Salient Features of Loctite 276 and 270:

  • It is a high strength thread locker that gives maximum output.

  • It shuns the loosening by vibrating and is ideal for gearboxes, pumps, and presses.

  • It is perfect for every type of metal which includes aluminum, stainless steel, and plated surfaces.

The Loctite 270 and 276 are the perfect products for this. These are high strength threadlocker fit for the job.

The Loctite 270 and 276 are the perfect products for this. These are high strength threadlocker fit for the job. These are perfect for bolts that have the danger or end use of vibrating a lot, this vibration leads to unscrewing of the bolts.

Loctite 290 – Wicking

locktite 242

The wicking can sometimes confuse people. It is designed to penetrate inside existing bolts on the threads.

This is done to apply the threadlocker without any need to disassemble anything. This product would go down inside the threads then hold the bolts super tight.

Loctite 290 is a powerful new glue from Loctite that bonds almost anything to anything! This powerful formula bonds on contact and remains flexible.

So it can handle the stresses of everyday life. Loctite 290 is the strongest, most versatile, most durable, and most long lasting adhesive from Loctite!

Frequently Asked Questions:

Do you need a premier for Loctite 242?

Yes the Loctite 242 does need a primer. Which is why the 243 is the better option. Which is a middle strength nut locker. This prevents the loosing of the fasteners, but can be easily loosened with hand tools. So by the Loctite 243 would not need a primer but 242 does.

Which Loctite is the strongest?

The red thread locker from Loctite is the highest strength. It takes 24 hours to cure, so always go for 270 or a 276. These are so strong that they would be needing a lot of heat to unscrew them.

Is the Loctite 242 oil resistant?

No, it is a drawback that the Loctite 242 has. If you want to use the Loctite 242 on threads which have oil on them, then you first need to clean them before using the 242. But this is not the problem with the Loctite 243 which has oil tolerance, so you can use it even if the surface has oil.

How much time does the Loctite 243 take to dry?

After the usage when the parts are assembled, torqued and tightened correctly, it hardly takes 10 minutes to set and for fully curing it takes 24 hours.

Final thoughts:

The Loctite is without a doubt the most efficient adhesive in its league. There are also hundreds of good products to choose from. But our article was mainly about Loctite 242 and 243. These are indeed one of the best threadlockers out there. And if you have to choose between these two then definitely you should go for Loctite 243.