Henkel, whose brands include LOCTITE®, is on a mission to demonstrate the importance of locking threaded assemblies against vibrational self-loosening and has released a powerful new video and education guide to support the initiative
We all know that there are several different methods of addressing the problem of self-loosening in threaded fastener assemblies, and many of them include the use of mechanical devices to lock threads and maintain the desired clamp load. Common amongst these are a double nut that increases contact through more thread interface, a spring washer to increase bolt tension through its spring action or perhaps a nylon insert which creates interference between itself and the bolt threads.
However, the limitation of all these methods, says Loctite, is that none tackle the gap that exists between the threads of the bolt and nut. This gap may be miniscule, but it is still large enough to allow lateral movement of the bolt itself within the nut, something frequently caused by operational vibrations across a wide spectrum of frequencies. This movement can eventually cause a bolt to loosen, regardless of any mechanical device used to lock it.
Henkel’s new video shows how catastrophic such a failure can be. It lasts less than a minute but leaves the viewer in no doubt that allowing a threaded assembly to go into operation unlocked is neither a sensible nor a safe option. It can be viewed here.
Loctite has also published an accompanying thread locking e-book, released in conjunction with the video, which expands on the reasons why threaded assemblies can fail. It provides a comprehensive introduction to the merits of adhesive thread locking, either as a stand-alone solution or to complement a mechanical thread locking device. It also guides the reader on the choice of adhesives available and how to disassemble a bolted joint or fixture once it is thread locked.