Frequently asked questions

LOCTITE is the trusted choice for adhesives, sealants and surface treatment solutions in maintenance, repair and manufacturing segments. Invented nearly 66 years ago with a unique liquid resin that hardens in the absence of air, LOCTITE solutions help make machines and assemblies more reliable, unlocking the limitless potential of man and machine.

Threadlocker is a chemical liquid that helps to secure nuts and bolts against self-loosening due to vibrations. LOCTITE Threadlockers work on anaerobic technology that hardens in the absence of air and presence of metal ions. So, when LOCTITE threadlockers are used on bolt and the nut is tightened, the liquid spread covering all the microscopic gap between the nuts and bolts and unitize them against loosening.

When LOCTITE products are in their packaging, like other products, they too have a duration when they perform the best. The shelf life varies by technology. For the anaerobic technology adhesives (threadlockers, thread sealants, retaining compounds and gasketing compounds) which LOCTITE is the forerunner in, the shelf life is 2 years.

LOCTITE adhesives that work on anaerobic technology which includes most of the threadlockers, thread sealants, retaining compounds and gasketing compounds work only on metal. Other technologies for example instant adhesives work on other materials like plastic, rubber, wood etc.

Threadlocker is applied on the threads of the nut and bolt and then it is bonded together. The liquid adhesive spreads evenly between the nut and bolt and then hardens into a thermoset plastic in the absence of air and presence of metal ions, locking the nut and bolt together and that is how LOCTITE threadlocker works.

LOCTITE 243 can simply be applied on the nut and bolt threads and then it can be assembled using hand tools. You can watch the how to apply video on this link - https://youtu.be/ZkfwVChgWKM.

LOCTITE threadlockers helps in preventing thread galling. When applied before the assembly, threadlockersLOCTITE threadlockers ensure that there is no galling by providing adequate lubricity in threads.

Leaking threaded joints can be fixed using LOCTITE thread sealants. LOCTITE 577 is the go-to product for sealing threads since it can fill in large gaps between threads of the metal pipe joint sealing the pipe.

The low and medium strength LOCTITE products can be disassembled using hand tools itself while the high strength LOCTITE products need heat to disassemble. You can watch how to disassemble threadlocked assemblies on this link https://youtu.be/Egz8gaNV6oM, and disassembly of assemblies sealed with thread sealant here - https://youtu.be/WUuC0htcxSI.

Yes, LOCTITE threadlockers can be removed as and when needed. The low strength grade of LOCTITE threadlockers can be removed by giving a loosening torque which is higher than the tightening torque. The medium and high strength LOCTITE threadlockers can be removed by applying localised heat (250 degrees celsius) to the part, for disassembly.

All LOCTITE threadlockers have the property of fluorescence. When you disassemble, you can easily find out by white powder on the bolt, that whether LOCTITE threadlocker has been applied or not. In uncured form, LOCTITE threadlocker can be identified by its color (Purple-Low strength; Blue-Middle Strength; Red-High Strength)

Yes. With LOCTITE 290, which is the wicking grade LOCTITE threadlocker, you can lock the nuts and bolts that are difficult to reach for application otherwise. You can just apply a few drops near the joint where the bolt head meets the part, and LOCTITE 290 will wick inside the nut-bolt interface due to capillary action.

No. LOCTITE threadlockers are thixiotropic in nature and hence don't tend to flow to other parts. Also, LOCTITE threadlockers only need to be applied on the nut-bolt interface and once the nut covers the area where LOCTITE threadlocker was applied, the adhesive will get cured in the absence of air and presence of metal, thereby turning into a thermoplastic, which cannot flow.

LOCTITE threadlockers come with a nozzle for precise drop-by-drop application. Hence, there is no scope for a mess. In case of any spillage, you can wipe it off easily because as long as LOCTITE threadlocker is in contact with air, it will remain a liquid and not cure at all.

Yes. There are some high strength threadlockers that can lock fasteners that are big and resist extreme vibrations. Please refer to the product selector tool.

The anaerobic bottles are specially formulated. Air-permeable polyethylene bottles allow air to pass through the wall. There is also some air gap over the product inside the bottle to maintain stability of the product. Thus a 50 ml pack of LOCTITE contains 50 ml adhesive in a much larger bottle.

The fixture time is the time taken by the adhesive to provide initial handling strength to the locked/sealed components. Once the fixture time gets over, you can take the assembled component for further processing on the assembly line.

The cure time is the time taken by the adhesive to completely become a tough structural solid (thermoset plastic).

Yes, you can. Normally we recommend retaining compounds like LOCTITE 638 for such applications, but threadlockers and retaining compounds both are same in terms of chemistry i.e. they are anaerobics. Inversely, you can use retaining compounds to lock threaded assemblies but the locking would then be permanent.

Anaerobics are generally not recommended for use with plastics as they might result in stress cracking or softening. In such cases, cyanoacrylates are recommended.

We recommend the use of primer where both the parts come under the category of 'inactive surfaces'. These metals lack the iron or copper content and thus the metallic ions are required to fully cure the product within 24 hours. These inactive surfaces include plated parts, stainless steel, galvanized steel and anodized aluminium to name a few. On the other hand, in case both or at least one part is an active metal, then there is no need to use a primer to ensure full cure which is typically within 24 hours at room temperature.

Yes. LOCTITE 243 can be used on oil impregnated parts, as it can cut oil effectively and lock properly. Just clean the part once before applying the product.

When we apply a threadlocker to a bolt, we hand tighten a nut down and let this sit for 24 hours to get fully cured. Now we take a torque wrench and break the bond, the torque needed to break the bond is the breakaway torque. Note that we haven't given any additional tightening torque to the parts. Thus, the breakaway torque gives us the strength of the threadlocker alone.

When we apply a threadlocker to a bolt, we finger tighten a nut down and let it sit for 24 hours to get it fully cured. Then we take a torque wrench and break the bond. After breaking the bond, we continue to turn the nut around by four quarters(360°), which provides us with the prevailing torque value. This shows us how much friction or drag is left to continue turning the nut.

When we apply threadlocker to a bolt, we tighten it by giving a tightening torque. The torque at which the nut can entirely be taken off is the breakloose torque. The main function of the threadlocker is to maintain the torque. It has been determined that over time, due to various factors like vibration, side sliding etc., there is a loss of upto 30% of the torque given to the parts. The goal is to select a threadlocker that would give you a breakaway value equivalent to 30% of the initial torque in order to maintain your torque over time. For eg: Let's say that a tightening torque of 10 Nm was given to the assembly. The breakaway torque (strength provided by the threadlocker) is 5 Nm. Now due to vibrations, there is a 3 Nm loss in tightening torque. So if you do not apply a threadlocker, your assembly tightened at 10 Nm will open at 7 Nm. Whereas, by applying a threadlocker, your assembly tightened at 10 Nm will have the total torque of (10+5) 15 Nm and even on 30% loss, it will open at 12 Nm, which is higher than your tightening torque. This is what is known as torque augmentation with LOCTITE threadlockers.

In order to ensure complete coverage and cure, apply LOCTITE threadlocker to both the male and female threads for blind hole applications such as a bolt going into a closed housing. If it is applied only to the male threads and torqued down, air pressure will force most of the product back out as you assemble.

Yes, heat can help achieve faster cure. Typically one can heat cure LOCTITE threadlockers at 125 degrees celsius for 1 hour, or go as low as 66 degrees celsius for 3 hours. The trade-off here is that there will be a reduction in strength to a certain extent. Please refer to the Technical Data Sheet of the selected product for testing the suitability.

We have developed a calculator to help you with the amount of LOCTITE threadlocker you need for your application.

To make the job of selecting the right product for your requirement easier, we have developed a product selector tool. Just enter your requirements and the tool will get back to you with the best solution.