In English it is known as Stainless, meaning without stains. In German it is known as Rostfrei, meaning rust-free. On the other hand, in French it is known as inoxydable, meaning stainless, and from this adjective we even use this abbreviation in Italy to refer to stainless steel.
Thanks to its versatility and versatility of use, this iron alloy occupies an important place in the daily lives of all of us.
What does stainless steel mean?
As we have written in this article on structural steel (link to the post on structural steel), the ferrous alloy known as steel contains carbon. However, when we talk about stainless steel, the recipe is a little more complex: in fact, it is the presence of 12-17% chromium in the alloy that determines its passivation capacity, that is to say, coating itself with a very thin layer of oxide that acts as a protection against water, oxygen and other agents and prevents rusting. The first patent for this alloy dates back to 1872, but its industrial application only began in the last century, after 1913.
Names and characteristics of the most famous stainless steels
The American Iron and Steel Institute (AISI) established the nomenclature for the steels currently in use, the AISI symbol to be precise, consisting of three numbers (the first of which identifies the category of steel according to the composition of the alloy) and possibly the addition of a letter that can indicate a low percentage of carbon (L, indicating good weldability, as we have seen here (link to post on weldable steels)), the presence of nitrogen ( N) or titanium (Ti).
There are several trade abbreviations for the most popular steels, but two deserve special mention: AISI 304 and 316, which are non-magnetic, low carbon steels.
The characteristics that distinguish these two alloys are.
Corrosion resistance and high temperature resistance
Easy to machine, weld and polish
Low maintenance costs
Long life of the artefacts
Good hygiene properties and easy to clean
It’s easy to see why they are so successful!
Uses of AISI 304 and 316
Stainless steel has one characteristic that makes it ideal for food use: it does not change the colour, smell or taste of the food it comes into contact with. This is why 304 is the most widely used for cookware and cutlery, and is also known as 18-10 steel, referring to its average percentage of chromium and nickel respectively. However, as it is not magnetic, it is not suitable for cooking on induction stoves.
Other important uses are for architectural and furniture decoration, as it does not rust or stain, and for tanks and structures in the chemical industry because of its high strength. A curiosity: even the spire of the Chrysler Building in New York City was built in stainless steel in 1929 and still gleams today.
Key differences
In short, we can say that AISI 316 differs from 304 because it contains molybdenum: the presence of this metal makes it more resistant to corrosion and, in fact, 316 stainless steel is used in the marine industry and in all objects that must be used in a marine environment and atmosphere.
Steel is also one of the most widely used metals in woodworking, just think of its use in industrial components, construction and furniture. Its versatility makes it suitable for different projects: if you have an idea and want to make a steel prototype, or if you need a single piece, a partner like Tisco steel can do it for you.
Tisco steel put all our expertise in your hands and, through the exclusive Project LAM formula, we also offer very high value-added services such as co-design and professional consulting. Give us a call to find out how we can help you.