The material we know as stainless steel (also commonly referred to as "Inox" or "Rostfrei") is such a common feature of 21st century living that there can be few of us who have not seen or handled articles made from it. But how many of us really know what stainless steel is?
Like all types of steel, stainless steel is not a single metal but an alloy that is a material made from two or more separate elements alloyed or "melted" together. What all steels have in common is that their major "ingredient" (alloying element) is the metal iron, to which a small amount of carbon has been added. Stainless steel was invented early in the 20th century when it was discovered that a certain amount of the metal chromium (usually a minimum of 11 per cent) added to ordinary steel gave it a bright shiny gloss and made it highly resistant to tarnishing and rusting. This rust-resisting property which we call "corrosion resistance" is what sets stainless steel apart from most other forms of steel.
It is important to appreciate that stainless steel is a solid material and not a special coating applied to ordinary steel to give it "stainless" properties. Conventional steels and, indeed, several other metals, are often coated or "plated" with white metals such as chromium, nickel or zinc to protect their surfaces or to provide other surface characteristics. While such coatings have their own benefits and are still widely used, the danger exists that the coating can be penetrated or damaged in some way, such that its protective effect is undermined.
The appearance of stainless steel can, however, vary and will depend on the way it is made and finished.
External tunnel cladding
Stainless steel is used to improve fire safety in tunnels. Photo courtesy of: Centro Inox
The architect chose stainless steel for the cladding of this structure because of its aesthetic qualities, both by day and by night. Photo courtesy of: Swarovski Project Build 2
Stainless steel water tank
Stainless steel water tanks provide an aesthetic finish and have a longterm durability. Photo courtesy of: Baoshan Iron and Steel
Stainless steel grid
Stainless steel can be woven into a grid. Photo courtesy of: null
Wales Millennium Centre
The dome of the Wales Millennium Centre is clad in 10,000 square metres of bronze-coloured stainless steel to withstand the weather conditions on the Cardiff Bay waterfront. Photo courtesy of: British Stainless Steel Association
Peter B. Lewis Building
250,000 lbs of stainless steel were used in the Peter B. Lewis Building of the Weatherhead School of Management in Cleveland, Ohio. Photo courtesy of: Weatherhead School of Management
Photovoltaic cell lining
Stainless steel precision strip is widely used in the lining of flexible solar photovoltaic cells. Photo courtesy of: Taiyuan Iron and Steel Co. Ltd. (TISCO)
You will find stainless steel in many everyday applications where good design, corrosion resistance and a long life are important. It is the ideal material to be used in commercial kitchens. Photo courtesy of: Michel Monteau
Vauxhall Cross bus station
London's second busiest bus station, Vauxhall Cross, has two mighty cantilevers that are clad in stainless steel. Photo courtesy of: British Stainless Steel Association
The first surgical implants in stainless steel were performed as early as 1926. Photo courtesy of: Nickel Institute
Cloud Gate Millennium Park, Chicago
The Cloud Gate sculpture in Chicago is made up of 168 stainless steel plates welded together and its highly polished exterior has no visible seams. Photo courtesy of: Shutterstock
The first stainless steel train was built in the USA in the 1930s. Photo courtesy of: Japan Stainless Steel Association
Apaté bridge, Stockholm
The Apaté bridge in Stockholm, constructed in 2002, was the first stainless steel bridge in Sweden. Photo courtesy of: Outokumpu
Washing machine drum
11 million washing machines using stainless steel drums were produced in China in 2010. Photo courtesy of: Miele
Petronas Towers, Kuala Lumpur
The Petronas Towers in Kuala Lumpur are the tallest twin buildings in the world. Photo courtesy of: Shutterstock