Your result

Locking ability

2,5 out of 5


1 out of 5

Worker safety

4 out of 5

Initial cost


Lifetime cost


How did we calculate?

Are nylon insert lock nuts effective
against bolt loosening?

Locking nuts work to secure bolted joints by adding friction to the thread of the bolt. Different varieties of locking nut exist, those that utilize metal to create friction, such as the all metal nut, and those that incorporate a polymer in the design, such as the nylon insert nut. Locking nuts follow the same installation procedure as normal nuts. The nylon insert nut features an internal nylon washer or patch.

The addition of the non-metal component means that the nylon insert nut is more temperature and chemical sensitive. It also necessitates the use of a tool for installation, however, the revolution speed must be less than 150 RPM in order to avoid over heating the nylon insert.

Read the full version in the eBook "Why do bolts loosen?"
(A comparison between common bolt securing options)
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Which bolt locking product should I use?

  • Pros & Cons of different bolt locking methods
  • A Guidance for Selection, to help you decide which product to use in your applications

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The biggest challenge for a bolted joint, causing it to lose preload and fail, is spontaneous loosening often caused by vibrationsThis Junker test shows all 5 nuts rotated loose! A steep decline in the graph indicates a failure. Read more about the Junker Test.

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