Breaking The (Color) Code: A Quick Guide To Threadlocker Colors

Threadlockers: A (Search) History

Although thread-locking adhesives have been around since the '50s, the question "What is threadlocker?" averages about 350 searches per month. And while the glue experts out there probably don't need a blog to tell them about threadlockers and how they work, our series on threadlocker adhesives is written for those browsing online for answers. 

Since we already covered what threadlockers are and other general questions in our first threadlocker blog, this one will take a more in-depth look at the different colors of thread sealants and how selecting the right color can impact an application and project.

That being said, here's a quick recap of what threadlockers are and why they are important:

Threadlockers prevent vibrations, heat, and other external forces from loosening mechanical fasteners. As mechanical fasteners are widely used in many industries for numerous critical applications, thread-locking sealants are an integral part of the safety and maintenance process. 

What Are The Different Colors Of Threadlockers?

Across most brands, thread sealants are typically available in different standardized colors for ease of use — each representing a specific strength and application. Understanding these different colors is essential to ensure the correct adhesive gets chosen for each job. 

Read on to learn more about the various threadlocker colors, their strengths, and when to use them.

Purple Threadlockers

Purple threadlockers are usually the lowest-strength thread-locking fluids. They are designed to provide temporary locking and are commonly used in applications that require easy disassemblies, such as: 

  • Instruments
  • Electronics
  • Small engines

Purple threadlockers can be easily removed with hand tools, making them ideal for applications that require frequent maintenance.

Blue Threadlockers

Blue threadlockers are medium-strength adhesives designed to provide an adequate amount of strength for most applications. Because they are more resistant to vibration, shock, and corrosion, they're suited for harsh environments and are commonly used in:

  • Motor vehicles
  • Machinery
  • Appliances

Blue threadlockers can also be removed with hand tools and are ideal for applications that require disassembly at a later time.

Green Threadlockers

Green threadlockers are medium to high-strength adhesives. Designed to seep into tight spaces, they are known for their low viscosities or wicking-grade properties and are ideal for already assembled fasteners like: 

  • Set screws
  • Electrical connectors

Green threadlockers are handy for touch-ups and maintenance on difficult-to-disassemble parts and machinery. 

Red Threadlockers

Red threadlockers are high-strength adhesives designed to provide a permanent bond. They are commonly used in applications that require a high degree of vibration and shock resistance, such as: 

  • Heavy equipment
  • Large machinery
  • Aircrafts

Red threadlockers require heat or a special solvent to remove, making them ideal for fasteners that will not need to be disassembled.

Don't End Up With The Wrong Threadlocker Color

Using the wrong color can result in ineffective locking, difficulty disassembling the fasteners or damage to the components. When in doubt, consult the manufacturer's specifications to help determine the best threadlocker color for your application needs.

If you are still unsure, have questions, or just need some advice on choosing the right threadlocker, an adhesives expert from would be happy to assist. Get in touch with us today!

Ask a Question

Have questions? Our team of adhesive experts can help. Submit your questions and we'll get you answers right away. We're here to help.