Loctite 242 vs. 271: what’s the difference?
Loctite 271 is intended for applications involving extreme vibration or situations where a loose bolt or nut could be extremely dangerous. It requires a temperature of 475 degrees Fahrenheit to release, which is per design. But what about Loctite 242?
Loctite 242 vs. 271: Specs & Uses
💪Strength
Loctite 242: Medium
Loctite 271: High
🆚Color
Loctite 242: Blue
Loctite 271: Red
🛠️Common Uses
Loctite 242 can be used to secure lens retaining rings, eyepieces, and optics kits; prevent bolts and nuts from vibrating loose in various parts of your vehicle, such as pellet gun bolts, rolling floor jack bolts.
Loctite 271 can be used to secure bolts and nuts in automotive applications, including engine components, suspension systems, and exhaust systems; effective for securing threaded connections in plumbing fixtures, like sink faucets, showerheads, or toilet parts.
Technical Info
My Hands-on Test of Loctite 242
✅ 242 to Secure Some Screws
I first used the 242 to secure some screws on my bicycle – the handlebar screws, brake levers, and pedals to be exact. Application was straightforward. I simply applied a small amount to the threads, being careful to avoid getting it on any painted surfaces as I wasn’t sure if it would damage the paint. Within minutes, the adhesive cured enough to draw the parts together snugly.
Loctite Threadlocker Blue 242 Nut/bolt Locker
let’s talk about the effectiveness of the Loctite Threadlocker in general. It’s clear that this product excels in its function, especially when it comes to securing metal components.
Next up, I had a metal pin that kept working its way out of the door piston on my truck every time the door opened and closed. A squirt of the 242 on the threads did the trick – that pin is locked in place and not going anywhere now!
One word of caution though – this thread locker is meant for securing threaded fasteners, not necessarily bonding dissimilar materials like metal and plastic. For those applications, there are better adhesive options.
The Best Adhesive for Bonding Metal to Plastic
I also used this product to lock down some coax cable connections on my RV that always seemed to loosen up over time. So far, so good – the cables have stayed tightly secured through several trips with no loss of signal integrity. The 242 seems to work well for this type of application.
One nice feature is that Loctite 242 is non-flammable once cured. I was able to use it on some small engine parts without worries. It’s gasoline and gas vapor friendly when hardened.
This bolt used to get loose every ride but ever since I used this thread locker it hasn’t so I’m happy with this purchase and would recommend if you have the same problem
Loctite 248 Vs. 242: Automotive Repairs, Plumbing & Stainless Steel Without the Need for a Primer
Loctite Blue 242 is intended for use during installation and not for already assembled or installed bolts. I have successfully used both of them on stainless steel without a primer, and they worked just fine.
Loctite 248 is mostly similar. The blue variant is essentially the blue compound in a paste form
It effectively prevents bolts and nuts from vibrating loose, ensuring a secure fit. What’s even better is that it remains removable when needed. I can’t emphasize enough how much of a lifesaver this threadlocker has been in preventing unwanted loosening.
❌Skip It On Oil Pan
When it came to using this on an automotive oil pan, however, I decided to skip it. The instructions warn that it requires clean, oil-free surfaces for proper curing. Since that’s virtually impossible on an oil pan, I moved on to another project instead.
As for curing time, it does take a bit depending on the materials. The package says it can take over 24 hours to fully cure, but I found it set up enough to do the job within 10-30 minutes in most cases. If you need to remove fasteners secured with 242 down the road, hand tools should do the trick without too much difficulty thanks to its medium strength formula.
FAQ of Loctite Threadlocker Blue 242
Q: What’s the proper way to open the sealed tube? Can I simply poke a hole at the top?
A: To open the sealed tube, I would recommend using a thumbtack, safety pin, or a similar object to gently poke a hole into the flat tip of the tube. This method allows for better control and ensures droplet-sized application.
Q: Can Loctite Blue 242 be used for securing glasses, particularly the screws that hold the lenses in place?
A: No, Loctite Blue 242 is not suitable for use on glasses. For small screws like the ones holding lenses in place, I recommend using Loctite 222 instead.
Q: I’m planning to join two 20′ pieces of pipe together for a weather station pole that will be exposed to outdoor conditions. Which Loctite product would be most suitable?
A: In your case, I would recommend using the Blue Loctite 242 (See loctite blue vs loctite red), which is designed for larger gaps like pipe threads. It has a thicker consistency. However, if you anticipate the need to disassemble the pipe in the future, I suggest using regular pipe dope paste. If the pipe is meant to stay permanently assembled, no additional product is necessary, but be cautious of potential rusting.
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My Hands-on Test of Loctite 271
✅Pros
I rely on the Loctite threadlockers to secure leather straps with Chicago screws. It has significantly improved the longevity of our products. I have different variations of Loctite threadlockers to cater to specific usage scenarios. They allow us to maintain our manufacturing process with minimal changes, and they perform exactly as advertised.
Replacing the Screws on Outboard Water Case
I also use Loctite 271 when replacing the screws on my outboard water case. Given the significant vibrations experienced by Johnson outboards, I wanted a reliable solution to ensure the screws remained secure. The thread-locker worked perfectly, and I didn’t encounter any issues. I even had to remove one screw temporarily, and it came out without a problem.
Heavy-Duty Applications
Red Threadlocker 271 is a high-strength adhesive designed for heavy-duty applications. It provides a holding power of 3,000 psi on slip and press fit assemblies. It is particularly useful for locking studs and press fits securely. If you ever need to unscrew anything secured with the red threadlocker, make sure to use the blue version.
The 271 threadlocker seemed to be a good choice, but after firing around 60 rounds, the high temperature caused it to fail. In such cases, the 272 threadlocker 
may be a better option (More Details Here: Loctite 263 vs. 272). However, this was not a fault of the product itself, and it performed well under normal conditions.
Strength
I appreciate its strength when properly applied. It ensures that screws on my scope mount blocks remain secure without any chance of them coming loose. While it is possible to remove the screws if needed, it requires considerable effort and sometimes even heat. This is exactly what I want for critical applications where I don’t want any chance of the mount screws coming loose.
❌Cons
While the product itself is good, the packaging could be improved. It should clearly indicate that it is a liquid, as I was expecting a gel-like consistency. I accidentally dispensed more than I intended, and once it sets, it becomes challenging to remove.
Does Loctite 271 Work On Stainless Steel?
According to the Loctite 271 datasheet, Loctite 242 is better for low strength applications like automotive, light machinery, bicycles, etc. and less active substrates like stainless steel and plated surfaces
FAQ of Loctite 271
Q: Is Loctite 271 suitable for installing a gun sight, or should I consider something else?
A: It might be too heavy-duty for the task. This particular product, Loctite 271, was designed for larger threads with a 3/8+ hold. Using it on smaller threads, such as a scope mount for a gun sight, could make it extremely difficult to remove in the future due to the limited application of heat and torque. I would recommend using Loctite Blue, which is specifically designed for smaller threads.
Q: Would Loctite 271 be suitable for securing a muzzle brake on a rifle?
A: I would recommend using Loctite 271 before assembling the muzzle brake. It can provide additional security and stability.
Q: Can I use Loctite 271 for securing a Traxxas Slash 4×4 high pinion gear?
A: I have been using Loctite 271 for over 10 years on various applications, and I believe it would work well for you. I have used it on bolts to attach ring gears, and I think it would be very effective in your case. Thank you for your question.
Q: Is Loctite 271 effective for securing screws on the inside of a self-cleaning oven door that keep coming loose?
A: I would advise against using Loctite 271 due to the high heat generated during the self-cleaning process. Loctite 271 requires a temperature of 475 degrees Fahrenheit to release, which is per design. The oven can reach temperatures higher than that during the preheat or auto clean cycles. As long as the oven never exceeds 475 degrees, the product should hold tight. Personally, I love using this stuff.
Q: Can I use Loctite 271 on wood cabinets?
A: I doubt that Loctite 271 would work on wood or porous materials. Instead, I would recommend using wood glue (See ca glue for wood). Apply the glue and screw in the bolt once it has almost hardened.
I’m Ronald Stevens, a Mechanical Engineer obsessed with adhesives, glue, and all things sticky! My passion began in childhood when I’d always be the one playing with glue during arts and crafts. And I’d spend hours researching and experimenting. Happy reading, and remember: stick with the best, and you’ll never be stuck in a mess!
Feel free to contact me and join our discussion:
Should I apply Loctite Blue 242 to the doorknob set screw before or after screwing it in? Do I put a drop on top?
It's best to apply this to the screw threads before screwing it in. Make sure to use a very small amount, and apply it before the screw is fully inserted. Remember, less is more in this case.
Does Loctite 271 require the use of a primer? I'm working with stainless steel and aluminum.
In my experience, I didn't need to use a primer with Loctite 271. I used it on steel threads without even cleaning them. Once applied, the product hardened within minutes. Just to be safe, I waited 24 hours before using the assembled parts.