What Are The 3 Situations When Mechanical Fasteners Are Not The Ideal Choice?

Available in a wide variety of sized and thread patterns, mechanical fasteners are typically strong enough to maintain a strong bond between materials that would otherwise come loose with ease. Relying on friction and tension to ensure a sturdy bond, they can be unfailingly employed in numerous applications that use a nut and bolt fastening […]

Available in a wide variety of sized and thread patterns, mechanical fasteners are typically strong enough to maintain a strong bond between materials that would otherwise come loose with ease. Relying on friction and tension to ensure a sturdy bond, they can be unfailingly employed in numerous applications that use a nut and bolt fastening system.

Not only do they have a wide applicability, but they are also safe to use for outdoor project due to their high resistance to rust. Even in the unfortunate situation when the head of a screw begins to rust, the shaft will remain intact preventing the materials it holds from coming into contact with moisture and other contaminants for a while longer.

Furthermore, mechanical fasteners are equally easy to drive through and remove, making them a more forgiving option for certain types of projects. However, the aforementioned advantages of the mechanical fasteners are relative when compared to other fastening solutions. Following are three examples where you stand to benefit more from using other types of fasteners.

 

1. Applications that imply continued exposure to vibration

Perhaps the most notable advantage of a bolted joint over other types of fasteners is that they can be easily dismantled. While in some cases this is a highly desirable feature, it can also cause problems if the fastening solution comes apart unintentionally due to operational conditions. The most frequent cause of loosening is the side sliding of the bolt head or nut relative to the joint, a problem that is typically caused by vibration.

If you're looking for reliable fastening solutions for applications that imply exposure to vibration, then a welded joint constitutes a far better choice. Even though nut and bolt mechanisms provide incredibly strong connections, they are innately weaker compared to continuous metal in this particular situation. With a one-piece fastener, you don't have to worry about the relative motion occurring in the threads or about it breaking due to heavy stress.

2. Refastening can be more of a curse than a blessing

The ability of fastening and refastening a bolt can be perceived as a great advantage or a huge drawback. For instance, having a mechanical fastening system on your ski boots is highly desirable because it permits you to adjust the buckles and ensure the footwear is properly fitted. Optimally adjusting ski boots is not all about comfort, but they can also help you perfect your technique.

However, the same cannot be said about a similar system in an engine. In this case, a mechanical fastening mechanism is as waste of time, especially if you consider the high number of bolts included in a typical motor. Moreover, not all fasteners have creep resistance, so they will surely fail to perform at high temperatures. This is why studs are always preferred over bolts in this case.

3. Mechanical fasteners are very precise

Because mechanical fasteners consist of a machine-threaded cylinder and a shaft, they ensure a very precise bonding. This can be a problem for applications where an "approximate" bonding is necessary, such as the motorcycle tank bags. The tank bags incorporate magnets that hold the tank firmly, while still allowing you to pull it easily whenever needed. A fastener that doesn't hold firmly and permits easy maneuvering is preferable for this situation.