A steel building manufacturer has marked 100 years of steel fabrication, making beams used in constructing metal buildings, as well as creating special products such as gates for dam and canal systems.

Johnson Machine Works, based in Iowa, has made its mark across the world over a century, providing customized metal building products for projects around the world.

"We realize we're in this for the long haul. We manage this company for the longevity of it," said Jeff Johnson, the company's president and chief executive and great-grandson of the founder.

The company doesn't disclose financial figures, but says its revenue from sales of metal building materials has been growing steadily.

Johnson Machine is part of a competitive industry, said Scott Melnick, a spokesman for the American Institute of Steel Construction in Chicago.

The company is part of the steel fabrication industry, buying steel from suppliers and then cutting, bending and welding it into custom products, including beams and columns used to construct steel buildings.

Johnson said the company's main competitors consist of 30 to 40 regional and national steel building fabricators.

The firm produces anti-ram steel walls and poles used to protect metal buildings from, among other things, terrorist attacks.

Such products are used on the United Nations building in New York, the U.S. Embassy in London and the Prudential Building in Tokyo.

The company's beams and columns were used to construct some of the metal buildings on the Drake University campus in Des Moines and the John Deere Credit building in Johnston. Steel fabricated by the manufacturer is also being used to build new high schools in Central Iowa.

To produce its steel building materials, the company occupies about 180,000 square feet of space - four football fields - at two locations in Iowa.

Inside the buildings, steel is moved by overhead cranes and cut by large saws into the right size, with workers use welding equipment to create and manufacture the huge finished products.

To illustrate its longevity, the company began as an ordinary blacksmith shop run by David Johnson on one side of a livery stable.

The business's operation in the 1930s accelerated into projects such as fabricated steel used in bridge construction. The company continued to grow during World War II, making hulls for military craft and steel buoys for the U.S. Coast Guard.

Twice in its history - 1914, 1954 - the prefabricated metal building manufacturer had to recover from fires that destroyed its operations.