The term “Nyloc” is an abbreviation for nylon insert self-locking nut.
Nyloc nuts feature a nylon collar in the top portion of the nut that locks the nut in place by squeezing the threads of the bolt as the nut is tightened. This friction that is created prevents the nut from loosening.
Nyloc nuts can be re-used but it is not advisable, as their efficiency is reduced with every application, until eventually they become ineffective. The effective operating temperature of Nyloc nuts varies by manufacturer but as a rule of thumb we would advise extremes of -40C to +120C.
The thread on this type of nut can often (but not always!) be identified by the colour of the nylon insert, with blue signifying metric and white for imperial threads.
Type P nyloc nuts are referred to as full or standard nuts, whilst Type T nyloc nuts are referred to as thin. This designation is used for all thread and material types.
For further information please take a look at our guides and tips section.