Demystifying The Issue Of Torque When Using Fasteners

When using fasteners for industrial purposes, there are many technical issues that one has to be very clear about. One of these is how much torque the fasteners need to withstand. In a few cases, items such as hex lag bolts need to be used within a particular torque range in order to provide the […]

When using fasteners for industrial purposes, there are many technical issues that one has to be very clear about. One of these is how much torque the fasteners need to withstand. In a few cases, items such as hex lag bolts need to be used within a particular torque range in order to provide the service that they are expected to provide. Knowing as much about this as possible will make it for the technician to ensure that they end up with joints that will last long and perform the functions they need them to.

What is torque?

The technical definition of torque is the force needed to rotate an object around a point, normally an axis or a pivot. In the setting of fasteners, torque can simply be defined as how much force is used to tighten the fastener.

What is its relevance in fastening items?

Most of the time when using fasteners such as a hex lag bolt, you might not feel the need to measure just how much force you are using to tighten the bolt. Most of the time, the tightening is done in an intuitive manner.

However, there are times when the force with which the bolts need to be tightened needs to be exact. Examples of this include when fastening engines to a car, and also when engines are being mounted on a wing’s plane. The variables that determine how much torque should be used to tighten the fasteners depends on the desired outcome. For instance, in the case of a plane’s engine, it is necessary to make the front bolts less tight than the rear ones, so that in case of any breakage the engine can fall away to the back. In the case of a car engine, the torque needs to be just enough to ensure that the fasteners can withstand the heat, pressure and vibrations without coming undone.

How can you ensure that you get accurate torque figures in a particular fastener?

If you are fastening something and you need to ensure that the torque in it is gotten just right, there are a few things that can have an influence on accuracy. The most important of these is the torque wrench you use. Ideally, you should buy a high quality one and have it calibrated on a regular basis to make it reliable. The more you use the torque wrench, the more likely it is to become less accurate, and the more you will need to have it recalibrated.

The other factor that may people tend to neglect is the quality of the fasteners. For instance, if a bolt has threads that are not lubricated or which are stripped, the torque reading you are going to get from that bolt will always be wrong. This means that when doing fastening that is dependent on torque, it would be wise to carefully pick the fasteners and to make sure that their threads are not damaged when being put in place.

As long as you understand the above, it will be a lot easier for you to do fastener installation with increased precision.