Stainless Steel development

On the 2nd October 1913, the eve of the First World War, a routine report was written in the Brown-Firth Research Laboratory in Sheffield, the benefits of which we are still reaping today.

Its author, Harry Brearley, chief metallurgist at Thomas Firth & John Brown Limited, had discovered Stainless Steel. Although his discovery sprang from a need to improve the weapons of war, Brearley had produced a material with properties that continues to provide countless benefits to mankind.

By the time of Brearley’s report, Thomas Firth & John Brown Limited had a well-established reputation in the field of armaments, having been formed through the amalgamation of two companies with a history as suppliers of steel, components and finished products to both governments and private contractors alike.

Thomas Firth supplied steel to the Royal Small Arms Factory at Enfield for the manufacture of rifle barrels, bayonets and other components, and it was their steel that helped make the world famous Colt revolvers unique in their day by having steel barrels and cylinders, unlike most manufacturers at the time who doggedly stuck to the traditional use of wrought iron.

Brown’s had, amongst other achievements, pioneered the rolling of armour plate and made the armour for HMS Warrior – Britain’s first iron warship. Soon after the discovery of stainless steel, the company would launch another of Britain’s most famous warships – the ill-fated HMS Hood.

The amalgamation of the two companies in 1903 to become Thomas Firth & John Brown Limited, usually known simply as Firth-Brown’s, was a natural step in uniting their interests. Likewise, their close relationship with the government made them the natural company to turn to early in 1912 when the War Department was seeking a better steel for rifle barrels – one that would resist wear more effectively and give the rifles a longer service life.

Brearley began experimenting with steel containing chromium, since such alloys were known to be very resistant to wear and abrasion. Even as early as 4th June in 1912, he commented: ‘if we come to study the subject of erosion in detail then a steel low in carbon and containing say between 4 & 10% of chromium would seem to be promising material’.

By October of that year, after various experiments with steel containing 5.1% chromium, Brearley suggested that although these steels could provide a comparatively cheap steel for rifle barrels or gun tubes, ‘it appears desirable to make observations with steels containing much higher amounts of chromium’.

Alloys of steel and chromium were not new. Chromium had been discovered by a French chemist called Vauquelin in 1797, and by the early 1820s Faraday in England and Berthier in France were both experimenting with steel containing this newly discovered metal. Their steels contained less than 2.4% of chromium.

Berthier had blades made which performed well, but neither Faraday nor Berthier seems to have commented on any extra wear or corrosion resistance. Over the years, other metallurgists, especially in France, experimented with chromium steels but it was Brearley who first recognised the potential for wider applications of the high chromium steels he had been experimenting with.

Brearley had experimented with steel alloys containing 12-14% chromium and recorded in his report:

We found that this material had also unexpected anti-corrosive properties. Highly polished pieces which have been exposed to the atmosphere in the Chemical Laboratory for two or three weeks remain perfectly bright whereas ordinary mild steel becomes quite rusty. If in this respect it can be compared with 25% Nickel Steel it has one great [advantage] over it, viz – that it can be softened so as to be easily machinable and if required can also be hardened: 25% Nickel Steel cannot be hardened and it is very difficult to machine. The material would appear therefore to be especially well suited for the manufacture of Spindles (hardened), Gas and Water Meters, Pistons and Plungers for Pumps, Ventilators and Valves for Gas Engines, Blades for Turbines, Ornamental parts which require to be stong, certain forms of Cutlery etc. etc.

Early attempts to find practical uses for stainless steel focused on the production of cutlery, however, these failed because the cutlers treated stainless in the same way they had worked carbons steels – eventually, by heeding Brearley’s advice they succeeded and a new era in cutlery was born – or would have been if the government hadn’t commandeered all chromium steel for the war effort.

The first commercially available stainless cutlery was produced by R. F. Mosley under the trade name ‘Rusnorstain’. Eventually Firth’s began to produce stainless steel in bulk, marketed as ‘Firth-Brearley Stainless’ in recognition of Brearley’s momentous contribution.

Gradually, other forms of stainless steel were developed, allowing an ever increasing variety of goods to be made until it became almost universal in its applications, from kitchens to chemical and food industries, from the hidden depths of the human body to outer space. Sadly, the Firth-Brearley trade name did not continue – cutlery marked with it is very collectable by steel industry historians – and Harry Brearley’s name as the person who opened the door to all these possibilities for the benefit of mankind is almost forgotten.