Bessemer Steel Process

Illustration of the Bessemer steel production process
The Bessemer steel production process. Getty Images

The Bessemer Steel Process was a method of producing high-quality steel by shooting air into molten steel to burn off carbon and other impurities. It was named for the British inventor Sir Henry Bessemer, who worked to develop the process in the 1850s.

While Bessemer was working on his process in England, an American, William Kelly, developed a process using the same principle, which he patented in 1857.

Both Bessemer and Kelly were responding to a pressing need to refine the methods of manufacturing steel so it would be entirely reliable. 

In the decades before the Civil War steel was produced in great quantities. But the quality of it often varied widely. And with large machines, such as steam locomotives, and large structures, such as suspension bridges, being planned and built, it was necessary to manufacture steel that would perform as expected.

The new method of producing reliable steel revolutionized the steel industry and made widespread advances possible in railroads, bridge-building, construction, and shipbuilding.

Henry Bessemer

The British inventor of the greatly improved steel process was Henry Bessemer, who was born in Charlton, England, on January 19, 1813. Bessemer's father operated a type foundry, which made mechanical type used in printing presses. He had devised a method of method of hardening the metal he used, which made his type last longer than type made by his competitors.

Growing up around the type foundry, young Bessemer became interested in building things of metal and in coming up with his own inventions. When he was 21 years old, he devised a stamping machine which would be useful to the British government, which routinely stamped important legal documents. The government praised his innovation, yet, in a bitter episode, it refused to pay him for his idea.

Embittered by the experience with the stamping machine, Bessemer became very secretive about his further inventions. He came up with a method for manufacturing gold paint to be used for decorative items such as picture frames. He kept his methods so secret that outsiders were never allowed to see the machines used to add metal chips to the paint.

In the 1850s, during the Crimean War, Bessemer became interested in solving a major problem for the British military. It was possible to produce more accurate cannons by rifling the bores, which meant cuting groves in the cannon barrel so the projectiles would rotate as they exited.

The problem with rifling the cannons commonly used was that they were made of iron, or of low quality steel, and the barrels could explode if the rifling created weaknesses. The solution, Bessemer reasoned, would be create a steel of such high quality that it could reliably be used to make rifled cannons.

Bessemer's experiments indicated that injecting oxygen into the steel-making process would heat the steel to such a level that impurities would burn off. He devised furnace that would inject oxygen into the steel.

The impact of Bessemer's innovation was dramatic. Suddenly it was possible to make steel of high quality, and it quantities of it could be manufactured ten times faster.

What Bessemer perfected turned the making of steel into an industry with limitations into a very profitable venture.

Impact on Business

The manufacturing of reliable steel created a revolution in business. The American businessman Andrew Carnegie, during his business trips to England in the years following the Civil War, took special note of the Bessemer process.

In 1872 Carnegie visited a plant in England which was using Bessemer’s method, and he realized the potential of producing the same quality of steel in America. Carnegie learned everything he could about steel production, and began using the Bessemer Process at mills he owned in America. By the mid-1870s Carnegie was heavily involved in steel production.

In time Carnegie would dominate the steel industry, and high quality steel would make possible the building of factories which defined the industrialization of America in the late 1800s.

The reliable steel produced by the Bessemer process would be used in countless miles of railroad tracks, vast numbers of ships, and in the frames of skyscrapers. Bessemer steel would also be used in sewing machine, machine tools, farm equipment, and other vital machinery.

And the revolution in steel created also created an economic impact as a mining industry was created to dig the iron ore and coal needed to make steel. 

The breakthrough that created reliable steel had a cascading effect, and it would not be an exaggeration to say the Bessemer Process helped to transform all of human society.