Tension Control Bolts (TC Bolts)
Tension Control Bolts also known as tc bolts are used for high strength, steel to steel fastening. It is one of the most commonly used fasteners for high strength applications, even preferred over large hex bolts. The head is dome-shaped and is not designed to be driven with normal tools. It requires a special wrench to work with. Once it is installed, the bolt is deformed wherein the extension of the bolt is sheared off due to the torque. And its spline allows us to gauge when the exact amount of tension is reached by the bolts.
Properties of Tension Control Bolts
- Since these bolts come with a fiction grip connection, any slippage is prevented.
- In designs where fatigue is a crucial consideration, preloaded bolts like TC bolts are recommended. Due to they heavy preload, the tension across the structure is evenly distributed.
- If installed correctly, TC bolts are extremely adept at handling vibrations and ensure that the structure is not loosened. This is once again, due to the preload with which these bolts come in.
- In structures which involve swaying movement of heavyweights like cranes, preloaded TC bolts prevent the impact of load reversals. It ensures that the structure is sturdy and doesn’t loosen or disintegrate.
- In addition to preventing load reversals, TC bolts also eliminate any possible slips in connections, even across moment resisting components.
Benefits of using Tension Control Bolts
Like we mentioned below, these structural bolts are used for the construction of steel structures. Therefore, they are engineered to provide the structure with the highest longevity possible. In addition to that, they are easy to use and require only one person to install despite its complicated fastening mechanism. It comes with inbuilt functionalities to determine the tensioning required to hold the structure together and also helps the user achieve the same. This functionality allows the user to determine if the required tension is achieved regardless of the amount of torque applied in securing it.
- Higher grade steel and increased preloads facilitates the use of bolts with smaller diameters.
- Since torsional shear is not induced during tensioning, there will be no bolt relaxation.
- TC bolts do not need lock nuts as they are vibration resistant.
- The bolts are extremely easy to install and requires only one person.
- A single tool is capable of installing TC bolts of several dimensions.
- Only minimal tool maintenance is required.
- Reduced operator fatigue.
- No risk of Hand Arm Vibration Syndrome.
- Does not require heavy calibrated torque wrenches.
But this doesn’t free the tension control bolts of its own set of flaws, most of which will materialise upon its improper installation.
Problems with Tension Control Bolts
Although these screws can be installed by a single person in a very short span of time, it is often thought of as a complicated process. This makes a few construction owners prefer regular hex bolts for steel to steel fastening. But what should be understood here is that, once they are installed properly, they offer much greater advantages than regular structural hex bolts.
An important property of the tension control bolts that its users should always keep in mind is that they will corrode once they are removed from the packing and also lose their lubrication. This means that they need to be immediately fastened after being opened up. Another reason to immediately fasten the tension control bolts is that the shear forces of simply placing the bolts in the structure without tensioning them could put them in a bind. This will lead to structural deformation and reduce the load-bearing capacity of the bolts. Ultimately, the rust build up would mean that excess torque is required to fasten the bolts and inevitably break it or loosen it.
Job Site Storage of Tension Control Bolts
The proper job site storage of tension control bolts can easily mitigate the issues of installation. Apart from the correct job site storage of these bolts, it is crucial that you tension them right away instead of simply setting them up for better streamlining. Ensure that they are not removed from their storage positions until the time of their installation. Storage of the bolts in places of high temperature and high humidity can drastically reduce the operational efficiency of tension control bolts.
In the meantime, you can store them in airtight containers. This will prevent any adverse reaction with the natural elements, ensuring that the bolts do not rust away in storage. But not everyone will be able to secure such containers due to cost factors and storage inadequacies. In such cases, one can refrain from purchasing the tension control bolts until a few days before it is required.
For your vendors to provide you with a large number of tension control bolts in such short notices could be hard. This is why it is crucial to collaborate with vendors who specialise in delivering high-quality fasteners in a very short notice. We at ITA Fasteners are dedicated to providing excellent services for all our clients. We understand that time crunches happen more often than not and are always prepared to deliver. You can either schedule a delivery with us or place urgent orders. We will ensure that you never run out of the fasteners you need to make your construction a success.
An additional measure that you can take to ensure that the tension control bolts you use are secure is to calibrate the wrench you use to handle the different dimensions of the bolts. Ensuring that the bolts and wrenches are working dimensionally in tandem with each other is important to guarantee the correct tensioning of the high strength bolts. If your construction requires tension control bolts of varying dimensions in large quantities, we recommend that you put in the time and effort to calibrate the wrench individually. While this can be extremely time consuming, you are guaranteeing that you have taken all the necessary steps to deliver the highest quality of fastening. Or, you could use smart and electrical wrenches which perform the calibration by themselves.
Apart from construction, tension control bolts have made roadways into several other industries like power generation and automotive fields. These bolts are extremely versatile and can offer very high value for money. If their storage and installation are taken care of properly, they are one of the best fasteners for structural and steel fastening.