The construction of steel framed buildings has changed dramatically over the last 50 years. Originally the sums carried out for weight load and stress were done by hand and there was a great tendency to build everything like a battleship so it would stand up no matter what was done with it. Over the years the computer has allowed programmes to be developed that will produce a building complete for purpose at the cheapest rate possible. This usually means that the steelwork and associated materials are pared down to the minimum for the building to be constructed.Lag Bolt sizes
There have also been a number of changes to the erection systems of such buildings and there are a number of alternative systems and several of these may be used on the same building. Lindapter many years ago developed a system of clamps that could be used without the requirement of drilling and bolting. The system allows a very quick construction programme to be maintained without compromising the structure of the building and they have expanded that system to blend with the typical nut and bolt systems that were traditionally used.
One of the major problems with any steelwork construction is that at times it becomes difficult if not impossible to reach both sides of the joint to be made, either because there is very little room at the back to get a spanner into position to tighten the joint or because it is in a position where only one man can work in and two hands or more are needed or the joint is being made into a hollow steel beam.
To deal with this situation the Holo Bolt has been developed so that the joint can be made from one side only. In this case the two parts to be joined are presented together and a hole the diameter of the Holo bolt is drilled through both parts. The Holo bolt consists of a central threaded bolt which screwed through a double conical steel nut with the one cone facing towards (and one away from) the head. The bolt is usually made from a good quality stainless steel to retain the strength required in the joint. The steel bolt without the conical nut is passed through a cylindrical sleeve made of mild steel and with a series if cuts running along its length and the conical nut screwed lightly on to the cut end. The Holo bolt is pushed through the hole and tightened, as conical nut is pulled into the cylinder it spreads open and locks the two joining parts together. It is simple easy to do and very effective.