Steel Rises to New Heights

Forbes recently reported that the developer of the 828 meter-high Burj Khalifa (currently the world’s tallest building), is planning an even taller Dubai skyscraper scheduled for completion by 2018. Rivals of “The Tower” will include Saudi Arabia’s Jeddah Tower (under construction at 1,008 meters); Iraq’s proposed tower, “The Bride” (1,152 meters tall); and Tokyo’s proposed Sky Mile Tower (1,699 meters) scheduled for completion in 2045.

The fascination with skyscrapers began when steel framing and steel reinforced concrete made curtain-wall architecture possible, leading to the first skyscrapers, according to the World Steel Organization. In the 1960s, tubular designs replaced conventional steel framing in most buildings rising above 40 stories. Tubular designs use less steel and provide improved resistance to lateral loads such as wind and seismic forces.

In addition to the cold-formed steel that makes the construction of these amazing structures possible, tons of other steel products are used inside these buildings. Cold-rolled, galvanized and other flat sheet steel is used in the ventilation duct work, fire doors and office furniture. Cold-formed steel, also called light gauge steel, is popular in the construction industry because it can be easily prefabricated and mass-produced. Cold rolling is a metal forming process in which a sheet of metal is pressed through a pair of rolls to reduce thickness, increase strength and improve surface finish. The cold-rolling process happens at ambient temperature, below the steel’s recrystallization temperature. This process changes the mechanical properties of the steel to produce uniform, lightweight steel with a high strength-to-weight ratio.

According to the American Iron and Steel Institute’s (AISI) Cold-Formed Steel Profile, cold-formed steel products were used successfully in building construction as early as the late 1920s and early 1930s, but were slow to catch on because at the time there was no standard design methodology available, nor was cold-formed steel included in the building codes.

AISI convened the Committee on Building Codes in 1938 to develop a specification for the design of cold-formed steel structures. In 1946, the first Specification for the Design of Light Gage Steel Structural Members was published, and in 1949, the first Design Manual for engineers was published. After the second edition was published in 1956, the Specification was formally adopted by the building code body, leading to greater acceptance of cold-formed steel products.

Modern cold rolling mills are able to achieve high speed production of sheet steel that meets a variety of requirements for thickness and uniformity with the help of an x-ray thickness gauge. Thickness gauges detect and correct deviations in thickness in real-time to achieve high quality steel strip. Read Optimization of a Cold Rolling Mill with a High Speed X-ray Thickness Gauge to better understand the role of the thickness gauge in a mill, learn about the standards to which all gauging systems should be held, and to see how a modern high speed X-ray thickness gauge can be used as a tool to optimize an cold rolling mill.

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