Generally thread locking compounds follow a colour coding system. It does depend on brand to some degree, but most commonly green is the weakest, blue medium and red strong.

Green locking compounds need a force of around 10Nm to release and flow well so are good for fine threads and getting into nooks and crannies. Medium strength blue usually requires 12-15Nm to break, and red around 25-28Nm.

Most thread locking compounds are thixotropic, which means there properties change under certain conditions. More often than not they set in oxygen-starved conditions, so when a bolt is tightened down, the oxygen is expelled and the thread-lock will cure.

Don't mix thread lock with grease and also avoid using it on aluminium bolts and screws as the additional force required to break them free will cause them to shear.

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