GlueOnline Guide to Threadlockers

Liquid thread locker adhesives or threadlockers, replace traditional mechanical locking methods and come in a variety of colours and viscosities. Below we have put together a short guide to threadlockers and some frequently asked questions.

What are threadlockers? 

A threadlocker is an anaerobic single part adhesive used to bond and seal threaded metal fasteners like nuts and bolts.  The adhesive is applied between two mating threads and cures in the absence of air, forming a strong thermoset plastic that locks the threads in place. Their primary use is to reduce fasteners loosening due to vibration or impact.

Grades of threadlockers include:

• Permanent and removable grades
• High temperature grades
• Different levels of strength
• High and low viscosities

What are the benefits of threadlocking adhesives? 

• Prevent loosening due to vibration or thermal expansion
• Seal against corrosion and leakage
• Fast cure speeds
• Gap fill abilities to prevent contamination
• Reduce vibration
• Act as a thread lubricant
• Reduced inventory than traditional locking devices
• Protect and strengthen various types of threaded fastener
• Reduce costly failures, repairs, and downtime
• Levels of strength for disassembly

Where are threadlocking adhesives used? 

Threadlockers are used to secure fasteners from vibration, impact and contaminants across industries including:

• Automotive
• MRO
• Aerospace
• Manufacturing
• Marine
• Electronics

What is the importance of the viscosity of threadlockers?

The viscosity determines how the threadlocker will behave when applied, lower viscosities will flow into gaps like water allowing them to be used for preassembled applications, while higher viscosities are better for larger gaps that require less penetration.

What do the different threadlocker colours mean?

Threadlocking adhesives are available in different colours which typically refer to different strengths and viscosities:

• Purple - low strength, medium viscosity
• Blue - medium strength, medium viscosity
• Green - high strength, low viscosity
• Red - high strength adhesive

How do you choose the right threadlocker? 

Choosing the right threadlocker depends on application requirements such as the size of the threaded components, the vibration levels, the type of metal, whether disassembly is required, temperature requirements and so on.  

For example, a high strength threadlocker is better suited to applications which do not require disassembly with hand tools, and a low viscosity adhesive is suitable for preassembled fasteners.

Speak to our technical team for a consultation to help find the appropriate threadlocker for your application.

Products to consider:

Permabond A1042 Rapid cure, medium strength threadlocker – suitable for disassembly and galvanised zinc coated steel, WRAS approved

Permabond MM115 medium strength anaerobic threadlocker – reliable on steel, cadmium, zinc and other plated fasteners, Mil spec available

Loctite 222 Purple low strength threadlocker – easy disassembly with hand tools

Loctite 243 Blue medium strength threadlocker – high temperature performance and oil tolerance

Loctite 290 Green medium to high strength threadlocker – wicking grade for preassembled fasteners, Mil spec available,

Loctite 277 Red High strength threadlocker – for permanent locking and sealing, Mil spec available