Bessemer Patents Improved Steel-Processing Method

Henry Bessemer patented and perfected a forced-air process that permitted the large-scale commercial production of steel. The new process created a steel product that was superior to the existing commercial products of cast and wrought iron. The Bessemer process was an important step in the provision of large quantities of steel needed for industrialization.

Summary of Event

The nineteenth century’s Industrial Revolution Industrial Revolution;and iron[Iron] required large amounts of iron and steel products. During the first half of the nineteenth century, only cast and wrought iron could be produced commercially in the quantities needed for industrial purposes. Both materials had significant disadvantages. Cast iron (2 to 5 percent carbon) can be cast into shapes easily but is brittle. Wrought iron, which uses very little carbon, is malleable but cannot be cast into shapes. Steel, which contains up to 2 percent carbon, can be cast and is also malleable. However, until the mid-nineteenth century, it could be produced only in small and expensive batches. After Sir Henry Bessemer introduced the first commercial method of mass-producing steel, steel began replacing both cast and wrought iron for industrial and military needs. Bessemer, Sir Henry
Steel;Bessemer processing
Iron;and steel[Steel]
Inventions;Bessemer steel process
Great Britain;steelworking
[kw]Bessemer Patents Improved Steel-Processing Method (1855)
[kw]Patents Improved Steel-Processing Method, Bessemer (1855)
[kw]Improved Steel-Processing Method, Bessemer Patents (1855)
[kw]Steel-Processing Method, Bessemer Patents Improved (1855)
[kw]Method, Bessemer Patents Improved Steel-Processing (1855)
Bessemer, Sir Henry
Steel;Bessemer processing
Iron;and steel[Steel]
Inventions;Bessemer steel process
Great Britain;steelworking
[g]Great Britain;1855: Bessemer Patents Improved Steel-Processing Method[3050]
[c]Inventions;1855: Bessemer Patents Improved Steel-Processing Method[3050]
[c]Manufacturing;1855: Bessemer Patents Improved Steel-Processing Method[3050]
[c]Engineering;1855: Bessemer Patents Improved Steel-Processing Method[3050]
[c]Science and technology;1855: Bessemer Patents Improved Steel-Processing Method[3050]
Kelly, William
Mushet, Robert Forester
Thomas, Sidney Gilchrist
Gilchrist, Percy Carlyle

A son of an engineer, Bessemer was born in Charlton, Hertfordshire, England, on January 19, 1813. Like his father, Bessemer enjoyed working on technical problems, and he was a lifelong inventor. His first invention was embossed revenue stamps for use on title deeds to prevent the reuse of stamps from older deeds. He later came up with a simpler solution of dating the stamps, but he was never credited with the idea.

Bessemer was more successful with his invention of a mechanical means of producing brass powder (gold dust) for decorative purposes. He was able to keep the process secret, and the resulting business made him wealthy. It was his experimental mortar shells that he patented in 1854, which led him to his work in improving the steelmaking process. The existing cast-iron gun barrels were not able to handle the new shells, so Bessemer decided to find a way to make commercial quantities of higher quality steel that could handle the mortar shells.

Sir Henry Bessemer.

(Library of Congress)

Bessemer set up a small iron-working facility in St. Pancras (north London) to experiment on the steelmaking technology. He decided that the answer was to force air through the molten pig iron to remove the desired amount of carbon rapidly. The reaction also generated enough heat to eliminate the need for additional fuel to keep the process going. The air blast was cut off when enough carbon had been removed. The converter that he developed to hold the process was able to handle large batches of iron very quickly. Bessemer patented his forced air process in 1855 and made a public announcement of it at the Cheltenham meeting of the British Association in 1856.

There was great interest in Bessemer’s paper, and iron masters immediately applied for licenses to use the new process. However, their initial trials would prove unsuccessful, as their products often turned out brittle. Bessemer remained confident and started his own commercial steelworks in Sheffield to perfect the process. The main problems were caused by oxygen left by air blasts and sulfur and phosphorus impurities found in many iron ores. An English metallurgical chemist Chemistry;and steel[Steel] , Robert Forester Mushet Mushet, Robert Forester , found a solution to the oxygen problem in 1856. He discovered that the addition of spiegeleisen (manganese-rich pig iron) removed the oxygen. Mushet patented the idea, but when the patent was allowed to lapse, Bessemer was free to incorporate this step into his process in 1859. Bessemer never conceded the need for the Mushet addition to his process, but he did provide some modest support to Mushet, who had financial difficulties.

Swedish iron master G. F. Goransson found that using iron ores low in phosphorus prevented the steel from being too brittle. The use of high-phosphorus iron ores was made possible in 1878 when it was discovered by Percy Carlyle Gilchrist Gilchrist, Percy Carlyle and Sidney Gilchrist Thomas Thomas, Sidney Gilchrist that a lining of limestone or dolomite for the converter with the additional of lime to the molten metal removed the phosphorus and sulfur. Bessemer patented a tilting converter in 1860 that made the loading and unloading of the converter easier. With the solving of the two chemical problems and other improvements, Bessemer’s Sheffield operations became a commercial success. The growing competition from Bessemer’s Sheffield works forced the other iron masters to apply for licenses to use his process.

Bessemer’s claim to have invented the forced-air process is not without controversy. The American developer William Kelly Kelly, William had been working earlier on a pneumatic (air-boiling) process to produce steel that was very similar to Bessemer’s forced-air process. Kelly, unlike Bessemer, had kept his work secret and rushed to patent his idea after Bessemer’s 1856 announcement. He received his patent in 1857. Kelly had initial success defending his American patent, but elsewhere in the world he was unknown; furthermore, his process had not seen the perfection evident in Bessemer’s process.

Over time, the process became solely identified with Henry Bessemer, and William Kelly received no recognition or royalties for his efforts. Did the two men develop their ideas independently, or did one get the idea from the other? Disagreement continues.

For Bessemer, the Bessemer process and his steelworks at Sheffield proved financially successful. It is estimated that he had received more than one million pounds sterling in royalties alone before his patent expired in 1870. Bessemer also received public recognition for his contributions to the creation of the steel industry. He was knighted and made a fellow of the Royal Society in 1879. Bessemer remained active as an inventor for the remainder of his life, but his later inventions did not have the impact of his steelmaking technology. Bessemer died in 1898 in London.


The Bessemer process was an important step in improving the use of iron for industrial and military purposes. The iron industry in England had been able to develop the use of plentiful coke (coal) to replace scarce charcoal (wood) and to produce malleable wrought iron in commercial quantities to replace brittle cast iron during the eighteenth century. However, wrought iron could not be cast, and this limitation was preventing technological advancements. The Bessemer process was able to provide large quantities of steel commercially for the first time. The superior quality of steel over cast and wrought iron allowed for product improvements and was a key driving force of the Industrial Revolution. The Bessemer process also led to the development of steel alloys (Robert Mushet Mushet, Robert Forester developed tungsten steel, for example), providing additional technological advances in steel products.

Although the last Bessemer converter was not closed until 1975, the importance of the process began to decline with the development of the competing open-hearth furnace in the 1860’s. Both processes were used for many years, but the open-hearth furnace replaced the Bessemer converter over time because of the advantages it had in recycling scrap metal, in larger batch sizes, and in quality control. The open-hearth furnace suffered a similar fate during the mid-twentieth century, when it was replaced by the superior technology of the basic oxygen furnace.

Further Reading

  • Bessemer, Henry. Sir Henry Bessemer, F.R.S.: An Autobiography. Reprint. Leeds, England: Maney, 1989. A reprint of the original 1905 work. Henry Bessemer’s own view of his life and his invention.
  • Bodsworth, C., ed. Sir Henry Bessemer: Father of the Steel Industry. London: IOM Communications, 1998. A modern biography of Henry Bessemer and his achievements. Includes a bibliography and an index.
  • Misa, Thomas J. A Nation of Steel: The Making of Modern America, 1865-1925. Baltimore: Johns Hopkins University Press, 1995. Chapter 1 discusses the Bessemer process and its importance to the industrialization of America.
  • Singer, Charles, et al., eds. The Late Nineteenth Century, 1850 to 1900. Vol. 5 in A History of Technology. Oxford, England: Clarendon Press, 1954-1958. Although the Bessemer process had pioneered the making of steel, the open-hearth method ultimately outproduced it in the twentieth century. This volume presents the most readable introduction to both means of steel manufacturing.
  • Wengenroth, Ulrich. Enterprise and Technology: The German and British Steel Industries, 1865-1895. New York: Cambridge University Press, 1993. Chapters 1 and 5 discuss the Bessemer process and the resulting steel product in the context of the European steel industry of the day.

Krupp Works Open at Essen

Glidden Patents Barbed Wire

World’s First Skyscraper Is Built

Brooklyn Bridge Opens

Eiffel Tower Is Dedicated

Related Articles in <i>Great Lives from History: The Nineteenth Century, 1801-1900</i><br />

Sir Henry Bessemer; Andrew Carnegie; Sir Robert Abbott Hadfield; Alfred Krupp; The Siemens Family. Bessemer, Sir Henry
Steel;Bessemer processing
Iron;and steel[Steel]
Inventions;Bessemer steel process
Great Britain;steelworking