Posted on July 2, 2017
A square hollow section is a formed plate steel support used in the building of residential and commercial structures. A hollow structural section (HSS) can be round, square or rectangular in its exterior shape. These sections are ether cold-formed or hot-formed from plate steel. The resulting piece would then be classified by ASTM International standards as A500 quality steel or according to the new standards an A1085 before its use as a structural element.
When ordering a square hollow section, there are certain specifications that must be met. First the process used to form the metal must be one of the following: Seamless, Hot-finished Welded or Electric Resistance or Induction Welded. When manufactured, it starts out as flat steel plate that is rounded. When it is welded together and forms the mother tube, a series of shaping stands transform the mother tube into its final square shape.
The uniform geometry of the square hollow section’s structure allows for multiple-axis loading. It has uniform strength on its multiple cross-sectional axes. Therefore, it’s makes a good structural column, providing great resistance to torsion. This structural element is also used when filled with concrete as a “lally column”, a parking area barrier or a bollard. These concrete filled bollards are often found on wharfs and used as posts for shipping vessels to attach mooring lines in order to remain stationary while in port.
When the square hollow section is used as an I-beam it is far less stiff than the “H” shaped section or the “channel” section. The “H” and the “channel” sections are both more stable I-beam supports.
Before placing your order for a square hollow section, be sure to know the specifications. The necessary measurements that need to be provided before placing your order are the following:
- Size mm x mm
- Thick’s mm
- Corner Radius- External
- Corner Radius- Internal
- Area of Section cm2
- Second Moment of Area
- Radius of Gyration
- Section Modulus
- Plastic Modulus
- Torsional Constants- Inertia and Modulus
- Section Surface Area
The square hollow section will also need to be finished before shipping. It can be varnished, painted or oiled externally. Before shipping the square sections will be wrapped in bundles and secured with rope, wire or straps. All of the measured specifications are standardized. Still some requirements of your order can be customized according to your needs.
Square hollow sections have great applications in the construction of industrial buildings, amusement parks, playgrounds and spanning large portal frames. Because of their smooth outer profile, the surface doesn’t trap dirt or water; therefore, limiting corrosion reactions. Their pleasing appearance also creates an interesting architectural look, which often reduces the need for additional decorative treatments like paint or plaster.
These sections have many benefits including high torsional rigidity and resistance, compressive strength, increased tensile and compressive strength due to its construction. Finally, their higher strength to weight ratio allows for less steel needed in your construction project, thus saving you money. These qualities of the square hollow section helps simplify architectural designs and reduce overall material costs. As a structural member, it more than serves its duties of as a support.