Even though automotive industry shapes people’s perception of Usa manufacturing, and metal manufacturing especially, it isn’t the nation’s largest consumer of metal-not with a long shot. It’s commercial construction.
To reduce cost, builders have relied on design methods to reduce the quantity of stainless steel seamless tube a structure needs, or even reduce on-site erection time. One design avenue that has become significantly more popular inside the past two decades has become to make use of choices to the conventional wide-flange beam.
These beams have evolved into a competent building material associated with preference. But with regards to strength, the design in the wide-flange beam pre-sents an issue. It might span simply a certain distance (or “unbraced length”) before requiring support. Coming from a purely strength perspective, it would be far more efficient for beams to consider a circular, square, or rectangular shape, which could extend the maximum unbraced length. The more distance these structural members are able to span, the fewer braces and supports a building needs. Ultimately, this means builders can 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 will span greater lengths between braces. A square steel tube having a 3/16-in.-thick wall thickness has an allowable load of 79 kips more than a column duration of 32 ft., while a comparable wide flange (ASTM designation of W12 x 40) comes with an allowable load of 64 kips across the same column length (see Figure 2).
For years HSS are already used for their dramatic effect. Builders and architects used these people to make an artistic statement, not to save cash, which remains true most of the time today. But because HSS are really strong, architects can design buildings with less material. HSS also save on finishing costs, because in comparison to hollow section steel, tubular sections have less surface area to paint or fireproof. Combine this with the fact that tube production costs have fallen lately, and building with HSS begins to make real economic sense. This really is one major reason that requirement for HSS continues to be increasing ever since the recession, and it’s within this environment that the tube cutting laser is beginning to start new opportunities.
HSS represent a departure from many tube laser cutting applications that tend to use relatively thin-walled workpieces. Shops providing HSS often must handle workpiece weights (called “stick weights”) up to 2,000 pounds. These workpieces are not just long, but additionally large; 14-, 16-, and 20-in. diagonal cross sections aren’t uncommon.
To generate such large workpieces cost-effectively on a tube laser demands meticulous planning. It’s significantly more complicated than using a cutoff saw, additionally it adds far more value for the workpiece. Modern tube lasers have load/unload functions that can handle mill-length pipe and structural material.
This capability gives designers stainless steel seamless tube when it comes to designing for mated sections. Mating a round tube to a different one round tube seems simple, however the bevel required dexopky12 produce a tight fit-up in between the two sections can be very complicated, particularly when tubes are of different diameters or shapes, or if they intersect at unusual angles.
From an architectural engineering perspective, such angles may make the best transfer of loads and a lot efficient consumption of HSS. But towards the welder and fabricator, this kind of complicated joint can be a nightmare.