What is the difference between Loctite threadlocker colors?

Loctite threadlockers come in four different adhesion strengths, allowing them to be used in a wide array of applications. Their strength is easily identified by their number and color of the threadlocking substance. In short, to decide between the four options it will depend if you anticipate needing to disassemble the components in the future.

• Red: High strength, permanent adhesion
  • Select for high vibration applications where the components don’t need to be disassembled in the future.
• Green: High strength wicking, permanent adhesion
  • Select for high vibration applications for preassembled fasteners that don’t need to be disassembled in the future.
• Blue: Medium strength, removable with torque
  • Select to ensure components don’t come loose in the application and there is a possibility of disassembling the components in the future.
• Purple: Low strength, easily removable
  • Select for non-crucial applications and if disassemble of the components in the future is a known possibility.

Red Loctite threadlocker

Red Loctite threadlocker is considered to have high adhesion strength. It cannot be removed by simply applying torque, but requires special heat in combination with torque (or special chemicals) to disassemble the components after the red Loctite threadlocker has been applied. It is available in either a semisolid anaerobic or liquid form, and once applied to the threads it will cure in 24 hours. Common versions are: Loctite 262, Loctite 268, Loctite 271, and Loctite 272.

Green Loctite threadlocker

Green Loctite threadlocker is considered to have high adhesion strength for wicking. It is ideal for preassembled fasteners, like set screws. It cannot be removed by simply applying torque, but requires special heat in combination with torque (or special chemicals) to disassemble the components after the green Loctite threadlocker has been applied. It is available in a liquid form, and once applied to the threads it will cure in 24 hours. Common versions are: Loctite 270 and Loctite 290.

Blue Loctite threadlocker

Blue Loctite threadlocker is considered to have medium adhesion strength. It can be disassembled with high torque, but it is easier to disassemble with special chemicals and/or heat. It is available as a tape, semisolid, or liquid form, and once applied to the threads it will cure in 24 hours. Common versions are: Loctite 242, Loctite 243, and Loctite 248.

Purple Loctite threadlocker

Purple Loctite threadlocker is considered to have low adhesion strength. It can be disassembled with low torque with the same hand tool used to install it. It is available in a liquid form, and once applied to the threads it will cure in 24 hours. The most common version is Loctite 222.

Full Loctite product comparison

For a full comparison and selection guide on how to choose between different strengths of threadlockers, please see our threadlocker chart and selection guide.