What is Loctite 620 and When Should I Use It?
If you're working with threaded fasteners and need a reliable solution to prevent loosening, Loctite 620 is the right choice. It is a medium-strength threadlocker designed for non-permanent assembly, making it ideal for applications where disassembly may be required in the future.
- Loctite 620
- A medium-strength anaerobic threadlocker that prevents nuts and bolts from loosening due to vibration or shock.
- Anaerobic Adhesive
- A type of adhesive that cures in the absence of oxygen, typically used in confined spaces like threaded joints.
I was working on a motorcycle engine rebuild and needed a threadlocker that would hold the bolts securely but still allow for removal when necessary. Loctite 620 provided the perfect balance of strength and removability.
- Clean the threads thoroughly with a degreaser like Loctite SF 7061 Cleaner to remove oil and debris.
- Apply a small amount of Loctite 620 to the male threads of the bolt.
- Assemble the parts and tighten to the manufacturer’s torque specifications.
- Allow the adhesive to cure for at least 24 hours before subjecting the joint to stress.
How Do I Remove Loctite 620 Once It’s Cured?
If you need to remove a bolt that has been secured with Loctite 620, the process is manageable with the right tools and products. The key is to use a
Loctite cleaner or remover, such as
Loctite 7063 Cleaner or Loctite Power Grab Remover, to break down the adhesive. I once had to replace a wheel bearing on my car, and the bolts were locked with Loctite 620. Here’s how I handled it:
- Heat the bolt with a heat gun to weaken the adhesive. Be cautious not to overheat and damage surrounding components.
- Apply a Loctite remover to the threads and let it sit for a few minutes.
- Use a wrench or impact driver to loosen the bolt. If it still won’t budge, repeat the heating and cleaning process.
- Once the bolt is removed, clean the threads with a wire brush and Loctite SF 7061 Cleaner to remove any residue.
| Method | Time Required | Effectiveness |
| Heat and Loctite Remover | 10–15 minutes | High |
| Impact Driver Only | 5–10 minutes | Moderate |
| Chemical Soaking | 30 minutes–1 hour | High |
How Does Loctite 620 Compare to Other Loctite Products?
When choosing a threadlocker, it’s important to understand the differences between Loctite products. Loctite 620 is a medium-strength option, while Loctite 243 is a high-strength threadlocker used for permanent applications. Loctite Power Grab is a tackifier that enhances the performance of anaerobic adhesives. Here’s a comparison of Loctite 620 with a few other common Loctite products:
| Product | Strength | Use Case | Removability |
| Loctite 620 | Medium | Non-permanent assembly | Easy with heat and remover |
| Loctite 243 | High | Permanent assembly | Difficult to remove |
| Loctite Power Grab | — | Enhances adhesion | Not applicable |
I used Loctite Power Grab in combination with Loctite 620 on a set of bolts for a custom engine build. The Power Grab helped the adhesive bond more quickly and securely, especially in high-vibration environments.
What Do Users Say About Loctite 620?
Many users praise Loctite 620 for its reliability and ease of use. It’s particularly popular among mechanics, DIY enthusiasts, and industrial workers who need a dependable threadlocker that won’t permanently lock parts in place. In one case, a user working on a marine engine reported that Loctite 620 held the bolts securely even in high-vibration and high-moisture conditions. They also noted that when it was time to perform maintenance, the bolts came off without excessive force after using
Loctite 7063 Cleaner. Another user working in the automotive industry mentioned that Loctite 620 is a go-to product for assembling suspension components. They appreciated that it provided enough strength to prevent loosening but still allowed for disassembly when needed.
Other Products and Tools Related to Loctite 620
When working with Loctite 620, it’s helpful to have the right tools and products on hand. Here are a few that are commonly used in conjunction with Loctite 620: - Loctite SF 7061 Cleaner: A fast-acting degreaser for cleaning metal surfaces before applying Loctite. - Loctite 7063 Cleaner: A specialized cleaner for removing cured Loctite products. - Loctite Power Grab: A tackifier that improves the performance of anaerobic adhesives. -
Loctite Activator 7471: Speeds up the curing process of Loctite products. - Loctite Remover: A chemical solution for dissolving cured Loctite products. These products are essential for ensuring that your Loctite 620 application is both effective and long-lasting. Whether you're working on a car, motorcycle, or industrial equipment, having the right Loctite tools can make a big difference in the quality and durability of your work.
