SIC 1791

This category covers special trade contractors primarily engaged in the erection of structural steel and of similar products of prestressed or precast concrete.

NAICS Code(s)

235910 (Structural Steel Erection Contractors)

Industry Snapshot

According to the latest figures available from the U.S. Census Bureau, more than 4,238 establishments are engaged in structural steel erection, generating an estimated $8 billion worth of business. Major uses of structural steel include office and industrial buildings; commercial buildings, including retail stores, restaurants, and service stations; apartment buildings, hotels, and motels; warehouses; and highways, bridges, tunnels, and other transportation facilities. Single-family homes accounted for a very small percentage of the structural steel used in the United States.

The structural steel erection industry felt the effects of the U.S. economic downturn more than other construction related industries because it relied so heavily on commercial and industrial construction, both which saw growth slow dramatically in the early 2000s. Spending on commercial construction declined 1.6 percent in 2001, while spending on industrial construction declined 3.2 percent. The lone bright spot in the U.S. economy—residential construction—had little impact on the structural steel sector. Transportation spending had also been trimmed in various rounds of budget cutting during the early 2000s, although increased funding was expected to gain governmental approval in 2004.

Background and Development

French architects began using iron to form the framework of their roofs about 1780. By the 1830s they also were using a form of masonry reinforced with imbedded iron bars that is regarded as the precursor of reinforced concrete. English builders began relying on iron in the construction of factories about 1850, primarily in an effort to make the buildings fireproof. Columns, beams, and window frames were made of cast iron, while exterior walls were made of brick or stone. Many commercial

SIC 1791 Structural Steel Erection

buildings also used iron, with elaborate facades often constructed entirely of cast iron and glass.

Builders in the mid-1800s also used wrought iron, which could be hammered into a sheet and laid between wooden beams, or vice versa, for added strength. Iron plates also were sometimes riveted to the ends of these beams to create an early I-beam. The first I-beams made entirely of wrought iron were produced in Paris about 1847. The Trenton Iron Works in Trenton, New Jersey, began rolling wrought-iron I-beams in 1854. The first wrought iron I-beams produced in Trenton were shipped to New York where they were used to rebuild the six-story Harper Building, which had burned in 1853. The building also had a cast-iron front.

Bridge builders also began using iron to replace wood and stone in the late eighteenth century. Abraham Darby, an Englishman credited with originating the coke blast furnace, designed and built the famous Coalbrookdale Bridge over the Severn River in 1779, using wedged-shaped sections of cast iron to form the arch. The 100-foot bridge was still standing more than 200 years later. The first bridge in the United States made entirely of cast iron was built in 1840 and spanned the Erie Canal at Frankfurt, New York. The first railroad bridge made entirely of cast iron was built in 1845 at Manayunk, Pennsylvania.

In 1886, a bridge being built across the St. Lawrence River near Montreal needed to pass through part of the Caughnawaga Indian reservation. To obtain permission, the bridge builder agreed to hire local Indians. The Indians proved adept at the work, and several tribes, especially the Iroquois, later earned reputations for high-steel construction work.

However, bridges made of cast iron often shattered and collapsed under the tremendous weight of the steam locomotives, so bridge builders turned to wrought iron, which has greater elasticity under stress. Later, bridge builders turned to steel for even greater strength. The first bridge to use arches made of steel was built at Kuelenberg, Holland, in 1868, and spanned the Rhine River. The Eads Bridge, which was built in 1874 and spanned the Mississippi River at St. Louis, was the first bridge to use steel arches in the United States. The rest of the bridge was made of wrought iron. The first all-steel bridge was built over the Missouri River at Glasgow, Montana, in 1879.

Besides being used in bridges, steel was crucial to the erection of the world's first tall buildings. In the early 1850s, Elisha Graves Otis, an American inventor, developed an improved elevator with safety devices to keep it from falling. About the same time, Henry Bessemer in England and William Kelly in the United States developed a process that made it possible to produce large quantities of inexpensive steel. Together, the Bessemer process and the Otis elevator gave rise to the modern structural steel erection industry. Safe elevators made it practical to build taller structures, and cheap steel provided architects with a way to support taller buildings without relying on thick, windowless walls of masonry.

William Le Baron Jenney, a Chicago architect, built the first metal-frame skyscraper, the 12-story Home Insurance Building, in the mid-1880s. Jenney used an iron framework for the first six floors to carry the weight of the building into the foundation. He used steel beams for the top six floors. According to Douglas Alan Fisher in The Epic of Steel, the first building with a frame made entirely of steel probably was the Rand McNally Building completed in Chicago in 1890. By 1900, buildings had reached 30 stories. The Empire State Building, built in 1931, was originally 86 stories. It was later raised to 102 and remained the United States' tallest building until the Sears Tower in Chicago was built in 1972.

Current Conditions

The structural steel erection industry reflected general economic trends in the United States. With an economic downturn in the early 2000s, there was less construction of new factories and office buildings, which depressed the industry. In fact, by early 2003 the office vacancy rate had jumped to 16.5 percent, compared to 8.9 percent in 1998. Between 2002 and 2003 spending on office building construction declined from $43 billion to $39 billion. However, structural steel and prestressed or precast concrete remained the primary construction materials for large-scale projects, and the industry was expected to rebound with another spurt in new construction as the economy recovered in 2004 and 2005.

In the early 2000s, the United States also was becoming increasingly concerned with the deteriorating transportation infrastructure. With thousands of railroad and highway bridges needing repair, the outlook for the structural steel erection industry was strong, particularly with the likely passage of the TEA-21 Reauthorization Bill, introduced by the House Transportation and Infrastructure Committee, which earmarked billions of dollars for transportation. As a result, the employment outlook for this industry was also better than average.

Industry Leaders

The leading company in this industry in 2003 was Pitt-Des Moines Steel Service Centers Inc., which was sold to Reliance Steel and Aluminum Co. in 2001. Operating as a subsidiary of Reliance, Pitt-Des Moines reported revenues of $215 million in 2001. Second was Schuff International Inc., of Phoenix, Arizona, which reported $174 million in revenue in 2003.


Structural steel erection workers held approximately 107,000 jobs in 2002. Nearly 4 of every 5 worked for the construction industry. Very few were self-employed. Many were members of the International Association of Bridge, Structural and Ornamental Ironworkers. Hourly wages for structural steel erection workers in the early 2000s averaged $19.55 an hour, according to the Bureau of Labor Statistics. Earnings of these workers can be reduced due to poor weather and the short-term nature of the work in the construction industry.

Further Reading

Delano, Daryl. "Clouds Over Industrial Sector Won't Break Until '03." Building Design and Construction, May 2002.

"Draft TEA-21 Reauthorization Bill," Railway Age. January 2004.

U.S. Bureau of the Census. Economic Census 1997. Washington, DC: 2000. Available from .

U.S. Department of Labor, Bureau of Labor Statistics. National Industry-Specific Occupational and Wage Estimates. Washington, DC: December 2002. Available from .

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