From a labor standpoint, tension-control (TC) bolts are more than ideal. They only require one person to install them, and because of their spline, it is easy to tell when they are properly torqued. That being said, though TC bolts are easier to install than heavy hex bolts, problems can arise when installing them. Knowing the risks and problems that can occur during TC bolt installation is the first step to avoiding them.
Erecting Structures Using TC Bolts
When erecting a structure, workers will first place the TC bolts into the structure without tensioning them in order to make assembly easier. While this does streamline the assembly process, problems can arise when the TC bolts are left in the structure without being tensioned for too long. Often, the bolts can be left for days without being tensioned. Two problems can occur. The bolts are exposed to the elements, causing them to lose lubrication and rust. This can make the bolts difficult to install when the time comes. Also, the shear forces from being in the structure without being tensioned put the bolts in a bind. When this happens, they may not install correctly. The torque used to install the bolts goes up due to the friction of the rust, and the bolt can break.
Proper Jobsite Storage of TC Bolts
What can you do to prevent these problems with tension control bolts from occurring? It all comes back to jobsite storage. While it does make things easier to go ahead and put the TC bolts in their place in the structure, prolonged exposure to the elements can cause problems with the bolts. It is a good practice to either tension them as soon as possible (not days later), or forgo putting the bolts in their places until it is time to properly install them. In the meantime, store your structural bolting components in covered containers away from the elements. See our jobsite storage blog for more tips.
