Nord-Lock® together with a standard nut present a locking that is superior to locking nuts e.g. nylon inserted nuts.
Bolts that are locked by friction in the thread lose most of their preload through vibrations while those locked with Nord-Lock® only present a minor loss of preload mainly caused by settlement in the thread. Even after moderate tightening the bolt is safely locked when using Nord-Lock®.
One proof of the security is that the preload increases (rather than an instant drop) when turning the nut loose with a wrench. This is a unique Nord-Lock® characteristic.
Test report no. 375-130-91 carried out by the German TÜV confirms that after two million cycles the tension was maintained. An inspection of the washers showed that Nord-Lock® could be re-used safely.
