Loctite 242 vs 243 : Choose The Right Adhesive For You!

Loctite is a brand that always outshines when it comes to attaching surfaces. Though this brand produces hundreds of different glues, Loctite 242 and 243 are the most famous. These glues are the best in the industry because they’re thread lockers and are specially used by mechanics.

As they belong to the same category, they have many similarities, but there’re many features to compare Loctite 242 vs 243. Basically, Loctite 243 is the upgraded version of 242 that means if you’re a beginner, you’re likely to see a difference between them.

However, if you’re still curious about which is better: Loctite 242 vs 243, then walk with us to know more about them.

Quick Overview

Loctite’s Blue thread locker range includes both 242 and 243. They also belong to the medium-strength threadlocker range. You can use them to avoid vibration or encountered shocks losing any fasteners.

Now let’s get into more details of Loctite 242 and 243.

Comparison Table of Loctite 242 and Loctite 243

If you’re curious to know more about these adhesives, here’s a quick comparison chart.

FeaturesLoctite 242Loctite 243
TypeMedium strengthMedium strength surface insensitive
Item Volume6 mililiters50 mililiters
Weight0.16 ounces1.76 ounces
Specific Gravity1.071.08

Loctite 242

The Loctite 242 is known as the original threadlocker or all-purpose threadlocker. It’s a methacrylate-based thread locking glue that has medium strength and medium viscosity.

This one is used for the valve cover bolts that attach to the carburetor studs on the vehicle. For less active substrates such as stainless steel and plated surfaces, the fixture time for Loctite 242 is on average 10mins, but considering weather and surface, it can vary around 5 to 20 minutes.

Instead of using expensive nuts, you can use Loctite 242 as it requires normal disassembly with standard hand tools. Besides, it protects threads from corrosion.  

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loctite 242


  • Suitable for plating and stainless steel surfaces.
  • An anaerobic glue of medium-strength to ensure longevity.
  • Makes excellent bonds without the presence of air.
  • Prevents corrosion and leak threads.
  • An affordable item to buy anytime.


  • It takes more time to dry out.

Loctite 243

Loctite 243 is a general-purpose threadlocker. It has enhanced oil tolerance and surface insensitivity, and it’s also a medium-strength adhesive. 

Due to vibrations and stress, this blue crew prevents leaking in active substrates, such as steel nuts, steel bolts, metals, brass, and copper. As a result, it’s very resistant to corrosion and high temperatures.

However, it shouldn’t be utilized in food processing facilities or potable water systems with temperatures exceeding 80 degrees.

loctite 243


  • Prevents vibrating components from loosening.
  • Work with any metals, including passive substrates.
  • Lower tolerance of industrial oils contamination.
  • Allows disassembly using hand tools for maintenance.
  • Medium strength threadlocker with 360F resistance to temperature.


  • It’s a bit expensive product.

The Similarities Between Loctite 242 vs 243

They aren’t necessarily made to fulfill the same aim, even if glues are part of the same brand. These two types of glue are ideal for mainly mechanical tasks. These are the perfect products for  

Therefore, the first and maybe the sole resemblance of theistwo glue concerns their intended function. Moreover, one of the fundamental features of the glues is that they can be removed with regular hand tools.

In-depth Comparison Between Loctite 242 and 243

Regardless of the few similarities noted above, there’re still variances between Loctite 242 and Loctite 243.

The in-depth comparison between Loctite 242 and 243 are discussed below:

Oil Tolerance

Anyone who visits the mechanic’s area knows how oily the place is, meaning sticking something to that place will be challenging. So, in that case, the oil tolerance of glue means how quickly the glue can work on surfaces in the presence of oil.

However, these types of glue have amazing oil tolerance that will do the job quickly and perfectly. But they don’t have the same oil tolerance power.

Loctite threadlocker blue 243 has more tolerance power than Loctite 242.  Now, if you’re searching for a glue that can work on really greasy surfaces, then Loctite 243 is the best, but other than that, Loctite 242 will also work great.


The next factor that makes a considerable comparison between Loctite 242 and Loctite 243 is the capability of sticking or adhesion. 

Both Loctite blue 242 and 243 belong to the same category but have a different level of adhesion. Having said that, Loctite 243 steals the show here as well cause it makes a stronger bond than the Loctite 242.

But if you want a moderate bonding, you can go for Loctite 242. Basically, which glue you want it’ll depend on how much bonding you need. 


Now, you might wonder how simplicity can be a factor in comparing these two types of glue. Well, here simplicity means how easily, without any mess, glue can work on any surface.

With that in mind, the Loctite 243 is more oil resistant, and it eliminates the need first to dry the surface, making it extremely simple to apply. On the other hand, Loctite 242 needs more time to dry out, making it a bit complex.


There’s no doubt that quality is one of the main differentiating factors when comparing two things. Well, for these two types of glue, quality also plays a major role. 

As discussed previously, Loctite 243 has adhesion power and is easy to use, making it a better-quality product. However, that doesn’t mean Loctite 242 isn’t worth buying.

Loctite 242 is also made of some amazing properties and has top-notch services. But the fact is Loctite 243 is the upgraded version of Loctite 242, which makes it a bit low quality than the other one.

Time Consumption

When you’re searching for glue, you should consider the drying time. For example, if you want an adhesive for a very greasy area, you need a different glue, while for a less oily area, you’ll need another glue.

With that being said, comparing Loctite 242 and 243, timing is another important factor. Though both Loctite threadlockers take 24 hours to dry out still, Loctite 242 need extra minutes as you have to wipe up the place and make sure it’s dry enough to apply, making it time-consuming.

However, for Loctite 243, you can directly apply the glue without wasting more time. 


Loctite 242 is ideal for the normal thread fasteners that can be easily disassembled with the standard hand tool. It protects threads from rust and corrosion, as well as prevents loosening. 

Loctite Threadlocker Blue 242 is ideal for less active substrates like stainless steel and plated surfaces.

On the other hand, Loctite 243 works on active metals and passive substrates stainless steel, aluminum, and plated surfaces.


Both Blue product has a temperature range of -65 to 300 F degrees. That’s why you may heat a difficult bolt to about 270 F degrees Fahrenheit to loosen it up a little. You may also freeze the glue tube to increase its shelf life.

Which One To Choose Between Loctite 242 and Loctite 243

But the one thing that can change your decision is the buying price. Though both the product has decent price range if you’re on a tight budget, then Loctite 242 is the one you’re looking for!

Watch Video Loctite 242 vs Loctite 243

Except for Loctite 242 and 243, there is a wide range of Loctite threadlockers. So take a look here to have a quick overview of other Loctite adhesives.

1. Loctite 222

The Loctite 222 is a low strength thread locker. You can adjust screws, including the rear-linked head and set screws. However, it’s a threadlocking adhesive good for metals of low strength that may fracture while demounting, such as aluminum or brass. 

This type of adhesive operates on all metals, including stainless steel and plated substrates. Minor contamination due to industrial lubricants such as engine oils, prevention of corrosion oils, and cutting fluids is tolerant. 

Besides, this tool is appropriate for tiny threads up to a maximum size of M12.

The Loctite 222 adhesive tube is also known as a purple threadlocker because of its color. Also, the curing time is 24 hours, making it perfect for low-strength metal surfaces.

Loctite 222 Threadlocker


  • Easily removable components.
  • Prevents loosening of pumps, gearboxes, and presses on vibrating assemblies.
  • Requires standard hand tools to be disassembled.
  • Ideal for securing the low-film thread of adjusting tubes, coils, and set twists.
  • Particularly suitable for tiny thread dimensions.


  • It has low power and low viscosity.

2. Loctite 272

For permanent thread locking and screening of threaded fasteners, the Loctite 272 is a suitable option. In the absence of air, the product cures metal surfaces near each other and prevents stress and vibration loss, and leaking. Moreover, it’s a high-temperature threadlocker.

Loctite 272 is a metal locking compound with exceptional performance. This threadlocking adhesive is used for nuts, bolts, and fittings. Plus, it has good mechanical strength, which means that the lock does not fall into shock or vibration.

Lastly, this adhesive is a medium strength thread locker in red color. Besides, it has a fixture time on the steel of 10 minutes, brass 5 minutes, and stainless steel 15 minutes. 

Loctite 272 Strength Thread Locker


  • Prevents fitting or bolt loosening.
  • Leaves no residue on the surface.
  • Used with a wide range of fasteners.
  • Doesn’t leavy any stain to the surface.
  • Thermal stability of 450-degree Fahrenheit.


  • If used for tiny ones, it might be quite messy.

3. Loctite 270

If you’re seeking glue for permanent locking and sealant of threaded fasteners, then Loctite 270 is the ideal option. However, it’s a green product, and the cure time for this adhesive is approximately 10 to 150 minutes.

Loctite 270 is a high strength threadlocker for optimum sealing and sealing vibrant bolts, nozzles, and grips. The product is intended to lock components that cannot be loosened permanently. It works on all metals, including stainless steel, aluminum, and plated surfaces.

The use of industrial oils, e.g. motor oils, corrosion protection oils, protection fluid, and cuttings liquids, has proved the minor surface contaminations tolerance of Loctite 270. It can be dismounted up to 300°C by heating.

 Loctite 270 x 50ml Threadlocker High Strength


  • General threadlocker with high strength for optimal efficiency.
  • Prevents vibrating components from loosening.
  • Works with all metals, even passives.
  • Proved tolerant to mild industrial oils pollution.
  • Allows removal using hand tools.


  • For the high strength, it vibrates a lot that can be an issue

4. Loctite 290

Loctite 290 can enter the threads into existing bolts. The glue is applied without the need to decommission anything. However, this would go into the threads and keep the bolts very tight. 

It’s a robust Loctite glue that connects nearly everything, thanks to the incredible formula. This potent formula is bound to touch and flexibility.

Due to its low viscosity and capillary action, the substance wicks between engaged threads and removes the need to dismantle before application. 

It has a 20-minute fixture time and cures completely in 24 hours. This sealant resists leakage and loosening caused by repetitive oscillation or shock.

Loctite 290 Medium High-Strength Threadlocker


  • Green hue makes the adhesive used per connection easier to recall and label.
  • High strength adhesive that implies it is fastened permanently.
  • Convenient for metal surfaces.
  • For its high strength, only heat can dismantled it.


  • Suitable for only screws and bolts.

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1. Do you need a primer for Loctite 242?

A primer reduces the setup time and enhances the binding strength and torque on most binding surfaces when used simultaneously. If you want the Loctite 242 to work immediately after applying, you can use a primer.

2. Which Loctite is the strongest?

The strongest Loctite product Red Threadlocker. It is totally cured in 24 hours. Search the 270 or 276 locomotives. These are so powerful that fire is needed to break them. This is available in both liquid and semisolid anaerobic forms.

3. Is the Loctite 242 oil resistant?

Loctite 242 provides excellent temperature and oil tolerance. It tolerates modest surface pollution caused by different oils, including cutting, lubricating, anti-corrosion, and protective fluids. But compared to 243, Loctite 242 is less resistant to oil.

4. How long does Loctite 243 take to dry?

Loctite 243 can be utilized for impregnated oil components, as it can efficiently cut oil and securely lock. From different experiments, it clearly shows that Loctite 243 takes 24 hours to dry completely.

5. What color is Loctite 243?

Loctite 243 is an adhesive with a blue color that attaches and screws and seals metal nuts and bolts so that shocks and vibration prevent loosening.


Hopefully, till now, you’ve understood all the differences between Loctite 242 vs. 243. These blue threadlockers 242 and 243 are very common glues and have ruled the industry for many years with their unmatchable services. 

However, the 243 is undoubtedly an excellent attribute of oil tolerance. But the 242 will serve you fine if you don’t have a special requirement.

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