Stainless steel, in the form recognized and used today, was invented in 1913 by English metallurgist Harry Brearley in Sheffield, UK, during experiments to create erosion‑resistant gun barrel steel.

Key date and inventor

  • The commonly accepted invention date is 1913, when Brearley produced a chromium‑alloy steel that resisted rust and staining far better than ordinary carbon steel.
  • Brearley’s alloy contained about 12–13% chromium, enough to form a thin, protective oxide layer on the surface, which gave rise to the idea of “rustless” or “stainless” steel.

Earlier groundwork

Long before 1913, other scientists had already noticed that adding chromium to iron improved corrosion resistance:

  • In 1821, Pierre Berthier observed that iron‑chromium alloys resisted certain acids and suggested their use in cutlery.
  • In 1872, English engineers Woods and Clark patented high‑chromium iron alloys that were chemically resistant but too brittle for widespread practical use.

These earlier efforts laid the scientific foundation, but they did not yield a tough, practical stainless steel like Brearley’s alloy.

Why 1913 is considered “the” invention

  • Brearley achieved a workable balance of chromium and carbon, creating steel that was hard enough for knives yet could still be sharpened and used in everyday cutlery.
  • His “rustless steel” rapidly found commercial applications, especially in cutlery from Sheffield, helping cement 1913 as the landmark year when stainless steel truly entered modern industry.

TL;DR: When people ask “when was stainless steel invented,” the historically accepted answer is 1913, crediting Harry Brearley’s chromium steel as the first practical stainless steel, even though the science behind it was built up through the 19th century.

Information gathered from public forums or data available on the internet and portrayed here.