You can refer to the following URL and complete technical information about Hollow Structural Sections (HSS).
Association for the institution's website,
American Institute of Steel Construction

Steel authority of U.S. law journal's Web site (Modern Steel Construction (MSC this magazine that focuses on the specialized steel structures, part of emissions Institute AISC America.
Atlas Tube Inc., one of the largest construction site sections and tube manufacturers in the United States
The Forum CIDECT the expertise to design and postgraduate Tubular deals.