Exploring The Main Methods Of Tightening Threaded Fasteners

Threaded fasteners are used in many different settings these days. However, there are many times when people using them end up not benefiting much from them on account of not being able to use them properly. For instance, the issue of tightening the fasteners might seem trivial, but it’s actually something that has to be […]

Threaded fasteners are used in many different settings these days. However, there are many times when people using them end up not benefiting much from them on account of not being able to use them properly. For instance, the issue of tightening the fasteners might seem trivial, but it’s actually something that has to be done in a certain way in order to be effective. Simply tightening the fasteners without regard to the technical processes behind this can lead to many problems including damage to the fasteners or the item that is being fastened.

In order to ensure that the fasteners are tightened as much as possible, you will need to pay attention to how precise the preload is. Some of the techniques you can use to facilitate this include:

Angle control tightening

This is a method that has been used for quite a long time. It is normally used when the tightening is done with the help of power wrenches. It involves tightening the fastener to its elastic limit, and then further turning it by a particular degree beyond this point. The only problem with this method is that determining what angle to use can be a bit tricky, since it involves some experimentation. It is also very demanding on the fasteners, since they can only be used a limited number of times when this method of tightening is used.

Torque control tightening

This is by far the most popular way of managing preload when tightening fasteners. It involves first finding the torque needed to tighten a specific bolt, and then using this information to do the same. Such figures are normally found in the relevant technical tables, or by comparing bolt tension and preload. The latter involves figuring out what bolt tension you require, and then finding the corresponding preload needed to tighten it to this degree.

Heat tightening

This depends on the application of heat to the bolt. The bolt is then marked, and the entire assembly then given time to cool. This lead to contraction of the bolt, which in turn become constricted and ensures that preload is achieved. Heating is normally done through the application of a naked flame, a heating coil or other methods. One of the disadvantages of this method is the fact that it might not be practical when using smaller bolts.

Bolt stretch method

This is a method of tightening that involves the use of hydraulic tension devices, and is normally used for bolts that are larger than 20mm in diameter. A small hydraulic arm is placed on the nut and a puller is attached to the ram, and the entire bolt is then stretched. As you would imagine, this can only work when the threaded part of the nut extends past the bolt.

These are the main methods that can be used to tighten fasteners with ease. It’s important to use them when doing assembly, since they ensure that the entire system you are assembling has very high build quality. This promotes longevity and reduces the need for claiming repairs under warranty.