Even though automotive industry shapes people’s thought of U.S. manufacturing, and metal manufacturing specifically, it isn’t the nation’s largest consumer of metal-not with a long shot. It’s commercial construction.
To decrease cost, builders have trusted design solutions to reduce the amount of stainless steel seamless tube a structure needs, as well as to reduce on-site erection time. One design avenue that has been considerably more popular inside the past two decades has become to make use of options to the regular wide-flange beam.
These beams have become a reliable building material of preference. But in terms of strength, the form of your wide-flange beam pre-sents an issue. It may span only a certain distance (or “unbraced length”) before requiring support. From a purely strength perspective, it might be much more efficient for beams to take on a circular, square, or rectangular shape, which could extend the most unbraced length. The more distance these structural members can span, the fewer braces and supports a building needs. Ultimately, what this means is builders may use a smaller amount of what’s often their biggest expense: the structural metal itself.
Enter hollow structural sections, or HSS (see Figure 1). These round, rectangular, or square tubes have shapes that provide inherently higher strength and can span greater lengths between braces. A square steel tube by using a 3/16-in.-thick wall thickness comes with an allowable load of 79 kips over a column duration of 32 ft., while a comparable wide flange (ASTM designation of W12 x 40) has a allowable load of 64 kips across the same column length (see Figure 2).
For decades HSS happen to be utilized for their dramatic effect. Builders and architects used them to make an artistic statement, not to economize, and also this remains true on many occasions today. But because HSS are incredibly strong, architects can design buildings with less material. HSS also reduce finishing costs, because compared to hollow section tube, tubular sections have less surface area to paint or fireproof. Combine this with the fact that tube production costs have fallen recently, and building with HSS begins to make real economic sense. This is certainly one main reason that need for HSS continues to be rising ever since the recession, and it’s within this environment that this tube cutting laser is commencing to start new opportunities.
HSS represent a departure from many tube laser cutting applications that tend to do business with relatively thin-walled workpieces. Shops providing HSS often must deal with workpiece weights (called “stick weights”) as much as 2,000 pounds. These workpieces are not just long, and also large; 14-, 16-, and 20-in. diagonal cross sections aren’t uncommon.
To create such large workpieces cost-effectively on a tube laser requires careful planning. It’s far more complicated than utilizing a cutoff saw, additionally it adds considerably more value towards the workpiece. Modern tube lasers have load/unload functions that may handle mill-length pipe and structural material.
This capability gives designers stainless steel tubing when it comes to designing for mated sections. Mating a round tube to a different round tube seems simple, but the bevel required dexopky12 create a tight fit-up in between the two sections can be very complicated, especially if tubes are of several diameters or shapes, or maybe if they intersect at unusual angles.
From an architectural engineering perspective, such angles may produce the best transfer of loads and most efficient utilization of HSS. But on the welder and fabricator, this sort of complicated joint can be quite a nightmare.