Loctite 243 – Properties, Data Sheets, Applications, Buy
Loctite 243 Threadlocker is one of the world’s leading solutions for medium-strength locking and sealing of threaded connections.
In the following article, drawing on our experience as Loctite experts, we explain the product properties of Loctite 243 in detail, provide links to download the relevant data sheets, explain how to use Loctite 243, and let you know where you can buy Loctite 243 in Switzerland.
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Overview
Loctite 243 – Product Properties
First, we will provide a detailed overview of the product features of Loctite 243 threadlocker in several sections.
What is Loctite 243?
Loctite 243 is a medium-strength threadlocker. Specifically, Loctite 243 is a single-component, anaerobic, and thixotropic adhesive. It cures in the absence of air.
Loctite 243 prevents unsecured loosening and leaks caused by shocks, vibrations, and corrosion. This adhesive was therefore developed both for locking and for sealing threaded connections.
Loctite 243 is universally applicable, for example on active metals such as brass and copper, but also on passive materials such as stainless steel, aluminum, and galvanized surfaces. For this reason, Loctite 243 is also referred to as a universal threadlocker.
According to Henkel, Loctite 243 adheres even to most oiled screws as well as screws in their as-supplied condition without prior cleaning.
Overview of Technical Specifications
Here you will find the technical specifications for Loctite 243 threadlocker in a list format:
- Application: Threadlocking, sealing of bolted joints
- Application range: Universal
- Strength: Medium
- Chemical base: Dimethacrylate ester
- Curing: Anaerobic
- Secondary curing: Activator
- Color: blue
- Fluorescence: yes, under UV light
- Viscosity: 1,300 – 3,000 mPa·s
- Thixotropic: yes
- Operating temperature range: -55 to +180 °C
- Breakaway torque (M10 screws): 26 Nm
- Thread size: up to M36
- Oil-tolerant: yes
- Initial hold on steel (23 °C): 20–25% strength after approx. 30 minutes
- Initial hold on stainless steel (23 °C): approx. 20% strength after 1 hour
- Initial hold on brass (23 °C): approx. 5 minutes
- Operational strength (22 °C): 2 hours
- Final strength for steel (23 °C): approximately 24 hours
- Storage (unopened container): dry location, 8 °C to 21 °C
- Shelf life: 730 days
- Shipping: at room temperature (not frozen)
- Food processing: Approved under NSF Category P1 for use as a sealant in food processing areas where contact with food is not possible (regional approval)
- Residential drinking water systems: Certified to ANSI/NSF Standard 61 for use in residential drinking water systems and in commercial applications not exceeding 82 °C (regional approval)
- Specific gravity @ 25 °C: 1.08
- Manufacturer’s product code: L243
Loctite 243 Curing Time
The curing time of Loctite 243 (also commonly referred to as the “Loctite 243 drying time”) depends on the type of strength required, the temperature, the material to which the adhesive is applied, and whether activators are used.
Without the use of activators, Henkel specifies the following cure times for the respective strengths, depending on the material and temperature.
- Hand-tight strength on steel (23 °C): approximately 10 minutes
- Hand-tight strength on stainless steel (23 °C): approximately 10 minutes
- Hand-tight strength on brass (23 °C): approximately 5 minutes
- Functional strength (22 °C): 2 hours
- Final strength on steel (23 °C): approximately 24 hours
Using an activator can speed up the curing time. Such activators are used, for example, with passive metals (stainless steel, aluminum, coated metals) or at low temperatures (below 5 °C).
Loctite 243 Temperature
The temperature range of Loctite 243—that is, its operating temperature range—stands out among Henkel’s medium-strength threadlockers, ranging from -55 to +180 °C. This is because the medium-strength Loctite threadlockers 241, 242, 245, and 248, for example, can only be used in the temperature range of -55 to +150 °C.
Loctite 243 Strength
As far as Loctite 243’s strength is concerned, it is a medium-strength threadlocker.
Although Loctite 243 provides sufficient strength to prevent screws from loosening due to vibrations and impacts, this threadlocker can still be broken loose—and thus removed—using a standard hand tool. For an M10 screw, the breakaway torque is 26 Nm.
Loctite 243 Plastic Compatibility
According to Henkel, Loctite 243 is generally not recommended for use on plastics; this is especially true for thermoplastic materials, as stress cracks can form on them. Henkel recommends that users first test the compatibility of Loctite 243 with plastic substrates.
Shelf Life of Loctite 243
Loctite 243 has a shelf life of 730 days when stored in an unopened container in a dry place at a temperature between 8 °C and 21 °C (Shelf Life).
Once Loctite 243 has been opened, there is no information on how long the product can still be used. However, Henkel warns against returning any adhesive that has been dispensed back into the original container, as the dispensed adhesive may have become contaminated during use.
Hazard Information
The following hazard statements are provided by the manufacturer Henkel for Loctite 243:
- H317 May cause an allergic skin reaction
- H412 Harmful to aquatic life with long-lasting effects
Safety Information
The following safety instructions for Loctite 243 are provided by the manufacturer, Henkel:
- For private consumers only:
- P101 If medical advice is needed, have product packaging or label at hand
- P102 Keep out of reach of children
- P501 Dispose of contents/container in accordance with national regulations
- P273 Avoid release into the environment
- P280 Wear protective gloves
- P333+P313 If skin irritation or rash occurs: Get medical advice/attention
Comparison Tables
In the following comparison tables, you can compare the various Loctite threadlockers with one another—for example, Loctite 243 vs. 242:
Be sure to check out our article“Loctite Threadlockers—Low, Medium, or High Strength.”
Loctite 243 Data Sheets
In the sections below, we have compiled links to the most important data sheets for Loctite 243.
Loctite 243 Safety Data Sheet
The Loctite 243 Safety Data Sheet (SDS) is intended primarily for occupational safety. This Safety Data Sheet contains, among other things, information on potential hazards, the product’s chemical composition, first aid measures, firefighting measures, measures to address accidental release, handling, storage, physical and chemical properties, stability and reactivity, toxicology for humans and the environment, as well as disposal instructions.
You can download the Loctite 243 Safety Data Sheet here.
Loctite 243 Technical Data Sheet
The Loctite 243 technical data sheet lists, among other things, the product’s physical properties, specifies cure times for various materials and other factors, and provides instructions for use and application guidelines.
You can download the technical data sheet for Loctite 243 here.
Loctite 243 Regulatory Data Sheet
The regulatory data sheet for Loctite 243 lists prohibitions and restrictions, the inventory status, and substances of concern.
You can download the regulatory data sheet for Loctite 243 here.
Loctite 243 RoHS
The Loctite 243 RoHS document shows whether the product complies with the RoHS Directive, according to the manufacturer Henkel. RoHS stands for “EU Directive 2011/65/EU on the restriction of the use of certain hazardous substances in electrical and electronic equipment”; in German: “Directive 2011/65/EU of the European Parliament and of the Council of June 8, 2011, on the restriction of the use of certain hazardous substances in electrical and electronic equipment.”
You can download Loctite 243 RoHS here.
Loctite 243 Application
When applying Loctite 243, you should follow the manufacturer’s instructions. In the technical data sheet for Loctite 243 (March 21, 2022 edition), Henkel provides the following information regarding the use of this threadlocker:
Applying Loctite 243
First, note that Loctite 243 reacts quickly with air humidity. The tip and cap must therefore be kept clean. After using the product, screw the cap on tightly to prevent it from curing.
When applying the adhesive manually, Henkel recommends using a peristaltic hand pump to achieve an even application of adhesive.
When applying Loctite 243 threadlocker, proceed as follows:
1. Clean the surfaces to be bonded with a Loctite cleaner, such as Loctite SF 7063 or Loctite SF 7064.
2. If necessary, use an activator to increase the cure rate, such as Loctite SF 7240 or Loctite SF 7649, for example when bonding passive metals (stainless steel, aluminum, coated metals) or at low temperatures (below 5 °C).
3. Loctite 243 must be shaken thoroughly before use.
4. To prevent the nozzle from clogging with cured adhesive, do not let the tip touch any metal surfaces during application.
5a. For through-holes: Position the screw and then apply Loctite 243 where the nut will later be seated.
5b. For blind holes: Apply several drops of Loctite 243 to the lower third of the internal thread or to the bottom of the blind hole.
5c. Sealing applications: Apply Loctite 243 in a 360° ring around the start of the external thread. Leave the first thread pitch free. The material must be applied all the way down to the bottom of the thread. If the thread is larger and the gaps are wider, adjust the amount of product accordingly. The product should then also be applied in a 360° ring around the internal thread.
6. Assemble the parts and tighten them to the correct torque as usual; tightening must be completed before the adhesive reaches hand-tightness.
7. Cleaning the tools: If any of the product has cured, first soften it with a Loctite solvent and then remove it mechanically, for example with a wire brush.
Removing Loctite 243
To remove Loctite 243, i.e. for disassembly, normal hand tools are usually sufficient.
If loosening Loctite 243 with normal hand tools doesn’t work, for example with screws that have a very large clamp length ratio, the screw or nut can be locally heated to around 250 °C. Disassembly must then be carried out while the part is still warm.
In the case of corroded or seized parts, Henkel recommends using the product Loctite LB 8040 Freeze & Release before disassembly.
Buying Loctite 243 in Switzerland
In Switzerland, you can buy Loctite 243, for example, in the online shop of the Swiss Henkel distributor abovo. The following container sizes of Loctite 243 threadlocker are available at abovo and can be purchased individually:
Click here to go to the Loctite 243 product page in the abovo online shop.
Consultation on Loctite 243
If you still have questions about Loctite 243 threadlocker, we at abovo, the Henkel distributor, would be happy to answer them. Of course, we’re also happy to support you with information and advice on all other Henkel products from the Henkel Adhesive Technologies range.
Abovo AG, based in Selzach, Switzerland, has been an authorized distributor of Henkel Adhesive Technologies products for around 20 years; initially in the Henkel Electronics division and since 2022 also in the Henkel Industry division.
The best way to contact the Henkel experts at abovo is by telephone or e-mail:
- Telephone : +41 32 552 44 44
- E-mail: info@abovo.ch
If you contact us by e-mail, we will reply as quickly as possible.