Yorkshire and the Humber
Stainless steel was invented in 1913 by Harry Brearley of Sheffield, working for Firth Brown Steels (now called Sheffield Forgemasters). SAE 304 stainless steel is the most common stainless steel today, invented by Dr William Herbert Hatfield FRS in 1924 at Firth-Vickers known as Staybrite 18/8, a chromium-nickel steel. Many Swiss watches were mostly made out of Staybrite.
Stainless steel
Austenitic stainless steel is the largest family of stainless steels, making up about two-thirds of all stainless steel production. They possess an austenitic microstructure, which is a face-centered cubic crystal structure. This microstructure is achieved by alloying with sufficient nickel and/or manganese and nitrogen to maintain an austenitic microstructure at all temperatures from the cryogenic region to the melting point. Thus austenitic stainless steels are not hardenable by heat treatment since they possess the same microstructure at all temperatures.