Sheffield has earned an international reputation for metallurgy and steel production, with many innovations in these fields being developed locally.
These include Sheffield plate (a technique in which silver-plated copper was produced by fusing a thin sheet of silver onto a copper ingot), invented in the early 18th century by Thomas Boulsover, and the crucible technique (which allowed the manufacture of a better quality of steel than was previously possible), discovered by Benjamin Huntsman in the 1740s.
From the mid 19th century, Sheffield grew rapidly to become the foremost steel manufacturing centre in the world, with most of the great steel mills and factories based in the lower Don Valley. The development of alloy steels and the invention of stainless steel in 1913 gave an immediate boost to the cutlery industry along with the wide range of products still being manufactured in the city.
The latter was rendered obsolete in 1856 by Henry Bessemer's creation of the Bessemer converter, and it was in this century that Sheffield gained its international reputation for steel-making.
Stainless steel was invented in Sheffield by Harry Brearley in 1912, and the work of F B Pickering and T Gladman throughout the 1960s, '70s, and '80s has proved fundamental to the development of modern high-strength low-alloy steels.
The expansion of the British Empire and two world wars ensured increased prosperity during this time, however, the amalgamation of firms after WWII were subsequently swept away in the 1960's and 70's by the introduction of new technology and changing markets.
Today, Sheffield produces more steel than ever, but in a cleaner environment and with only a fraction of the workforce. Avesta, Sheffield's Shepcote Lane factory, has a capacity to produce more than 500,000 tonnes of stainless steel per year and is the largest supplier of high quality, hot rolled stainless steel throughout Europe and North America.
Innovative manufacturing technologies and techniques continue to be developed on the Advanced Manufacturing Park (AMP) by Sheffield's universities and other independent research organisations. Notable establishments on the AMP include the Advanced Manufacturing Research Centre (AMRC, a research partnership between the Boeing Company and the University of Sheffield), Castings Technology International (Cti) and TWI (The Welding Institute).