Loctite 221 vs 222: Brass, Stainless Steel, Bolts and Screws

What’s the difference between Loctite 221 and Loctite 222

Loctite 221 vs 222: Specs & Uses

Here is the info:

	Loctite 221	Loctite 222
Rating	★★★	★★★★
Datasheet	📥Loctite 221	📥Loctite 222
Description	Low strength threadlocker, allows easy disassembly with hand tools	Low strength threadlocker, allows easy disassembly with hand tools
Fluorescence	Positive under UV light	Positive under UV light
Viscosity	Low	Low, thixotropic
Cure	Anaerobic	Anaerobic
Secondary Cure	Activator	Activator
Breakaway Torque	5 – 12 Nm (M10 steel nuts and bolts)	6 Nm (M10 steel nuts and bolts)
Prevail Torque	2 – 8 Nm (M10 steel nuts and bolts)	4 Nm (M10 steel nuts and bolts)
Breakloose Torque	9 – 21 Nm (M10 steel nuts and bolts, pre-torqued to 5 Nm)	14 Nm (M10 steel nuts and bolts, pre-torqued to 5 Nm)
Max Prevail Torque	9 – 21 Nm (M10 steel nuts and bolts, pre-torqued to 5 Nm)	14 Nm (M10 steel nuts and bolts, pre-torqued to 5 Nm)
Compressive Shear Strength	3 – 10 N/mm2 (steel pins and collars)	≥2.5 N/mm2 (steel pins and collars)
Heat Aging	Retains 50% strength after 5000 hrs at 120°C	Retains 50% strength after 5000 hrs at 120°C
Chemical/Solvent Resistance	Generally good resistance to motor oil, gasoline, brake fluid, water/glycol, acetone, ethanol	Generally good resistance to motor oil, petrol, brake fluid, water/glycol, acetone, ethanol

My Hands-on Test: Loctite 221

✅Pros: Loctite 221

I used it on various applications, including screws, bolts, and even faucet handles or auto pan gaskets that may need to be removed in the future. It provided a secure hold while still allowing for easy removal when necessary.

Strong and Reliable

You can’t deny its strength and reliability. I’ve used it to mount optics and set screws for a long time. Plus, I don’t have to resort to extreme measures like jackhammers, chisels, or heavy sledgehammers to remove screws when I change my build. Be stingy when applying it, as a little goes a long way.

Low Torque Bolts and Screws

As well as screws and bolts with low torque, I’ve used Loctite 221 on glasses arms and many bolts on my cars. You can use this thread locker if the torque specification is low, don’t let the size fool you.

Versatility

Loctite 221 ensures that bolts and screws stay put, not just for automotive applications but also for other items like laptop screws. It seems anything that is upside down or subjected to frequent movement can benefit from this fantastic threadlocker.

Floor Lamp

I thought it would be perfect for a particular annoyance I had with a floor lamp. The lamp’s screw-on base was poorly designed, constantly loosing and impossible to tighten without damaging it. I applied threadlocker after cleaning the threads with alcohol.

After 24 hours, the base became resistant to casual unscrewing, and I haven’t been bothered with it since. The relief of never having to deal with that recurring annoyance again is worth the cost of the tube alone. I even find myself looking for other defiant nuts and bolts to secure with this excellent threadlocker.

Applying Loctite 221

My Hands-on Test: Loctite 222

✅Pros: Loctite 221 Alternative

Loctite 222 on the countersunk M4 bolts that hold the GoPro adaptor to the MCdeck 👇

Applying Loctite 222

It holds strong, yet it’s easy to loosen when necessary, making it an ideal choice for my needs.

Firearms

When it comes to firearms, some components cannot tolerate medium strength Loctite, as it can potentially strip screws and threads. That’s why I find this light strength variant to be perfect for such applications. It creates a snug lock without the fear of damaging or stripping any parts.

Loctite 222 vs. 243

Loctite 222 has lower strength, suited for applications requiring easy disassembly; Loctite 243 has medium strength for more demanding applications; Loctite 243 has better heat aging and chemical resistance; Loctite 243 provides higher breakaway and prevail torque.

I have also used this product effectively on gun sights. What impresses me is that it can be removed without heat, yet it holds tight, providing the reliability and security I require.

Testing Details

Here are some more details on my experience using it:

• Application: The purple liquid applies easily from the bottle with a drop on the screws before tightening them down. The nozzle dispenses just the right amount with a simple pull.
• Cure time: After about 15-20 minutes, the locker has mostly set up and provides enough holding power to keep the screws from loosening over time, even with repeated stress on the joints.
• Strength: It doesn’t lock so tightly that I can’t remove the screws later using hand tools, which is perfect for furniture that may need disassembly someday. I tested trying to remove a screw after 24 hours and it came out with some elbow grease but no power tools required.
• Value: The best part is the cost – around a quarter of what I’d pay for Loctite! And the bottle is massive compared to the tiny tubes of the name brand. I’ll probably never use it all before it expires in two years, but at this price I won’t mind buying more.
• Visual indicator: When you apply it, it’s a purple liquid. When you uninstall it, it leaves a purple frosted haze so you can see where you’ve applied it previously. This helps avoid over-application.

FAQ