ISO QMS Certified
"Our Science ... Your Success"

What does the color of threadlockers mean?

What do the threadlocker colors usually mean?

Years ago USA military specifications dictated the color of the liquid threadlocker inside the bottle.  The bottles are generally the same color.  Note: not all threadlockers are color coded according to this scheme.  The color scheme applies to the Mil Spec products (used in existing designs) and the new ASTM standards (for NEW designs).  So when in doubt, check the product number and technical data sheet for full information.

Here is what the threadlocker colors can indicate:

PURPLE THREADLOCKER – Low Strength

Permabond Purple Threadlocker LM113 is a Low strength Medium viscosity threadlocker which is ideal for small screws used in computers, eyeglasses, carburettors, and small electronic devices.  The low strength is ideal as it allows removal

GREEN THREADLOCKER – Wicking Grade for Post Assembly

Permabond Green Threadlocker HL126 is a High strength Low viscosity threadlocker.

BLUE THREADLOCKER – Medium Strength

Permabond Blue Threadlocker MM115 is a Medium strength Medium viscosity threadlocker.  Blue threadlockers are often called removable threadlockers as they can be disassembled with hand tools.

RED THREADLOCKER – High Strength

Permabond Red Threadlockers HM118, HH120, HM128, HM129 and HH131 are all high strength threadlockers.  These are often called permanent – but that really isn’t accurate.  Fasteners which have been locked with red threadlocking adhesive can be disassembled – it just isn’t quite so easy to do.  To disassemble apply localized heat greater than 550°F.  The adhesive/sealant will soften and can be removed.

Does this color coding apply to all threadlockers?

No, Permabond A011 is a low strength threadlocker that is red.  This product is sold in Europe and wasn’t made to meet the USA Mil Spec.

Do the anaerobic threadlocker color categories apply to other anaerobic adhesives and sealants – like retaining compounds?

No, the wicking grade threadlocker HL126 is green to indicate wicking grade but the high viscosity retaining compound, Permabond HH040 is also green.

So are all removable threadlockers blue?

No, Permabond MM115 PURE is colorless.  It is a medium strength medium viscosity threadlocking adhesive that is NSF ANSI 61 certified for potable water.

As always, we’d love to hear from you?  Please contact us with any questions.

AA Colors