Our daily life is surrounded by steel. There is steel in our cars, in the roads, in the railways, in buildings… It is fundamental in human activity, because no other material has its durability, plasticity and versatility. Its incredible qualities give rise to curiosities that are just as surprising as its malleability or even more so. Did you know that a kilogram of steel costs approximately the same as a loaf of bread? That every minute 700 tons of steel are recycled in the world? And that more than 90% of the water used to manufacture a ton of steel is also recyclable? These are just some of the many curiosities of this incredible alloy.
The Eiffel Tower
We all know the Eiffel Tower; the most emblematic example of metal architecture in the 19th century. But perhaps you don’t know the multitude of peculiarities that surround it. Its author, Gustave Eiffel, was an engineer who was an expert in the construction of bridges and railway stations and designed it for the Universal Exhibition in Paris in 1888, like most of the significant buildings of this architectural movement that emerged with the Industrial Revolution.
The tower was built entirely of puddle iron, a material that was approaching the composition of steel, as it could be hot-rolled. If it were built today using new steel technologies, it would be three to four times lighter. It is 321 metreshigh, making it the tallest building in the world until it was surpassed by the Empire State Building in New York in1931. Even so, it is still the tallest structure in Paris, and the fifth tallest in France.
Its weight is 7,300 tons; but it currently exceeds 10,000 tons due to the museum, shops and restaurants it now houses. In addition, in the summer it grows due to the thermal expansion of the metal: it becomes about 18 centimeters higher, and it can lean up to seven centimeters in the wind.
Every five years it is painted with 60 tons of paint to prevent material corrosion. That is why it has had several colors, such as yellow, red (its original color), gray and grayish brown. Since 1968 the color ‘Eiffel Tower Brown’ has been the choice in order to blend in with the Parisian landscape. It is graduated into three shades, from the darkest below to the lightest above, to visually play with the vanishing point.
Steel in the automotive world
The auto industry also offers us curious – and beneficial – data regarding steel, since it is the main material used in manufacturing cars. Thanks to the progress made in steel-coated sheets, car bodies have a 12-year guarantee against corrosion. The data can be overwhelming: car recycling in the United States alone generates enough steel to build 13 million new cars. Meanwhile, most manufacturers today still use steel over aluminum or any other material to build the vehicles of the future: the electric car.
Steel in our daily lives
A multitude of curious facts about steel fill our daily lives: steel is a material that is on the rise in fashion jewelry, our bags and backpacks can be made partly from steel wire, and cans of our favourite drink are getting progressively thinner: in 1975 they were 0.33 mm thick. In 2000, 0.23 mm. All our cans and food containers are made of steel, because it is odourless and does not corrode.
Approximately 60% of steel products are recycled at the end of their life. So maybe the can you’re drinking right now was once part of your car body, your bedroom radiator, your kitchen cutlery or the mobile phone you’re reading from right now.