Where visual assessment shows that the fastener might not have actually been sufficiently tightened up to avoid the removal of the nut by hand, the inspector will physically check for this condition for the fastener." While the 2009 meaning appropriated for setup and examination of snug-tightened connections, that meaning was found to be inadequate to specify a suitable starting point for the turn-of-nut approach of pretensioning bolts.
From a labor standpoint, tension-control (TC) bolts are more than ideal. They only need someone to install them, and since of their spline, it is easy to tell when they are properly torqued. That being stated, though TC bolts are easier to install than heavy hex bolts, problems can arise when installing them.
When erecting a structure, workers will first position the TC bolts into the structure without tensioning them in order to make assembly easier. While this does improve the assembly process, problems can arise when the TC bolts are left in the structure without being tensioned for too long. Frequently, the bolts can be left for days without being tensioned (Tension control bolts).
The bolts are exposed to the components, triggering them to lose lubrication and rust. The shear forces from being in the structure without being tensioned put the bolts in a bind.
What can you do to avoid these issues with tension control bolts from happening? Everything comes back to jobsite storage. While it does make things simpler to proceed and put the TC bolts in their place in the structure, extended exposure to the elements can cause issues with the bolts.
In the meantime, shop your structural bolting parts in covered containers away from the aspects. See our jobsite storage blog for more pointers. A325 Tension Control Bolts.
Essentially, standard structural bolts have a body length and thread length based on ASME requirements (Ref. Non-standard refers to bolts that are not on this chart, but can be custom-made made to fit consumer needs. Non-standard structural bolts can have unique attributes for example: a hex configuration rather of a heavy hex head, totally threaded structural bolts, and other non-standard features.
For structural bolts, these requirements consist of everything from body size and head height to thread length and identification symbols. Being most commonly purchased, basic structural bolts are usually kept in stock by the majority of producers and distributors. Because of this, there's a faster turn-around time than non-standard structural bolts. Non-Standard Structural Bolts Unlike basic structural bolts, non-standard may not follow all of the standards in the ASME.
It is necessary to discover a maker that is well versed in customized work. Interaction is paramount when buying non-standard structural bolts, so it is essential to opt for a business you can rely on.