Solution Tree for Threaded Fastener Loosening

While a variety of loading profiles can cause fastener loosening, it is understood that forces which lead to slipping of the clamped parts in the joint relative to one another will cause the most dramatic loosening. The force that resists loosening is generated by friction between the mating threads and between the bolt or nut and the mating part. In the standard bolted joint this resisting force is directly proportional to bolt tension – the greater the elongation of the bolt, the greater the friction force available to resist loosening. Because resistance to loosening similarly decreases with decreased bolt elongation, the common occurrence of joint relaxation due to embedment within the joint stack will leave the joint more susceptible to loosening.

The following flowchart identifies thee three primary means of preventing threaded fastener loosening and lists specific remedies for each.

  • Newsletter

    Each edition of ArchNews will bring you new fastening developments, including application data and test results. Read the Latest Edition Newsletter Archive

  • Have you thought about your joints lately?

    Learn how your view of fastening costs may be costing you money, and how to get a no-cost assessment of your worst joint problems. Click Here

  • Need more information?

    For more detailed information on any topic discussed on this site please contact us by phone at 248-377-1147 or email us at:

  • Certificate #2511.01

    View Scope of Accreditation