What the steel industry owes to bronze powders

Joe Capus, MPR consulting editor, looks back on the contributions of Henry Bessemer.

Henry Bessemer, an early manufacturer of bronze powder.
Henry Bessemer, an early manufacturer of bronze powder.

It is probably not widely known that Henry Bessemer (1813-1898), an English inventor of the 19th century, famous for his Bessemer converter steel-making process, actually built his initial fortune from the manufacture of bronze powder.

The prolific inventor, born 200 years ago, began his career in his father’s type foundry in Hertfordshire where he became “a skilled caster of decorative metal medallions”1. Later on he developed a process for the industrial manufacture of bronze flake powder for use in so-called ‘gold paint’, used for the decorative gilding of a variety of objects, a very popular business in the Victorian era. The existing gilt finish powder was hand made by craftsmen, for example in southern Germany, and was very expensive.

Bessemer studied the product and developed a way to mechanise the manufacture of bronze flake powder and set up production on an industrial scale with steam-powered machinery. He was able to produce the powder at a fraction of the cost of previous methods. He was determined to keep his production method secret and instead of applying for patent protection he went to extreme measures to maintain security at his plant. As a result he profited greatly and managed to keep his process secret for many years, a forerunner of the secretive nature of the PM industry in the following century. Bessemer’s bronze powder, although not designed for use in powder metallurgy, was clearly the first metal powder produced on a significant commercial scale. The powder was sold in large quantities and Bessemer made a fortune from it. The money he made from powder production allowed him to fund the development of the steel-making process for which he is mostly famous.

The Bessemer converter enabled the rapid and low-cost production of steel from molten pig-iron and resulted in a great expansion of production on both sides of the Atlantic and heralded the second industrial revolution. Not content with the great success of his Bessemer converter process, Bessemer went on to make many more inventions, filing a reported 129 patents during his lifetime. Meanwhile Bessemer was knighted in 1879 for his contribution to industry, and elected a Fellow of the Royal Society.

The Bessemer Gold Medal was established and endowed by Henry Bessemer in 1874 as an annual prize awarded by the Iron and Steel Institute (now The Institute of Materials, Minerals and Mining, in London, UK) for “outstanding service to the steel industry”2. Bronze flake powder is still in widespread use for decorative paints and similar pigment applications and is now produced by a number of companies in Europe, North America and Asia, but remains a small element in the current overall global metal powder picture.

References

1. “Henry Bessemer: Inventor of the Bessemer Converter”, Engineers, pp.228-231, DK Publishing, New York, NY, 2012.

2. www.iom3.org (The Institute of Materials, Minerals and Mining, London, UK)