Ever since threaded fasteners became mainstream, the problem of loosening of fasteners due to vibrations has increased manifold. What constitutes as a vibration-induced problem and how exactly does vibration cause the loosening of fasteners?
Causes of Vibrational Loosening
Resonance is everywhere. However, once it picks up a significant intensity, it becomes a vibration and acquires the ability to cause notable damage to fasteners. The effects of vibration can generally take weeks or months to loosen fasteners, but in places where violent machinery or powerful and wide movements occur frequently, the damage can happen almost instantaneously.
Even the smaller fasteners aren’t spared - when our electronic devices became smaller, the fasteners used in them also had to be miniaturised. Smaller and lighter fasteners were found to be more susceptible to loosening under vibration, making the fasteners that go into the manufacturing of our smartphones and computers vulnerable. These devices experience more vibrations due to the CPU’s fans and hard drives.
Preventive Measures
While it is virtually impossible to eliminate vibrations entirely, solutions to prevent its effects from manifesting are high-end and easily available. Here are a few ways in which you can solve the problem.
Screw Locking Inserts
These inserts provide a strong internal lock for fasteners - the inserts grip the nuts and bolts and effectively prevent the fasteners from loosening under vibrations. The biggest advantage of using screw locking inserts is the repeatability with which they can be used. They allow for easy assembly and disassembly without relaxing their grip on the fasteners, even with cast iron, stainless steel or titanium materials.
Belleville Washers/Disc Springs
Belleville Washers or Disc springs are innately self-dampening, especially when they are stacked in a parallel setup. They help with dispersing any inconsistencies in load distribution, which go a long way in protecting the entire structure from the bad effects of vibration. They also help prevent structural damage in case of shock loadings or falls.
Wedge Lock Washers
While several anti-vibration solutions rely on friction, wedge lock washers use tension to secure the fasteners in place. Wedge lock washers also offer improved operational reliability as they allow the structure to handle dynamic loads with ease. These washers drastically reduce the risk of operation-stalling, accidents and warranty claims.
Trilobular Threaded Screws
The thread profile of these screws is rounded yet slightly triangular. The recesses of the screw-head allow the target material to ‘creep’ around the fastener, making it more resistant to vibrations. However, please note that using trilobular screws is only a semi-permanent solution, as they lose their vibration-resisting abilities with repeated use.
Serrated Screws
If washers are unsuitable for the component or structure you are building, you could opt for serrated screws which ‘bite’ and ‘embrace’ the target housing. This naturally makes the structure immune to vibrations. However, like trilobular threaded screws, the threads of serrated screws will be damaged upon repeated use.
Locking Nuts
Locking nuts come with nylock sleeves which grip the threads of a screw after installation. The nuts have a series of tight threads on their elastic body and easily lock the screws in place. These nuts can also be repeatedly used for several years without risking any damage.
Pre-applied Fasteners
This is, by far, the most versatile solution for vibration resistance that you can go for. As the name suggests, these fasteners simply come pre-applied with adhesive. These thread-locking adhesives do not lose their grip over time or during any climatic extremities.
Vibrations induce unnecessary wear and tear on the fasteners, making anything you build with those fasteners unreliable. Irrespective of the duration of the vibrations felt or the size of the fasteners, it is crucial to stay insulated against vibrations to ensure the longevity of a structure or component. If you turn a blind eye to the effects of vibration, you could be looking at a potential structural failure.
We understand that structural integrity can literally make or break a component’s reliability and, in turn, your reputation as a builder or manufacturer. That’s why we invest the time in understanding your requirements and offer solutions to safely and effectively prevent vibrations from damaging your structure. We stock and manufacture all the products mentioned above and would love to give you a consultation on how to use them well. Do get in touch with us to know more
