One of the most important ways to categorise a metal, before other differences are noted, is if it is ferrous or non-ferrous. Other categories for metals include whether or not it is magnetic or not, ductile, or an alloy, but knowing if it’s ferrous is vital.
Where does the word ferrous come from?
The word ferrous derives from the Latin word ‘ferrum’, which means iron (chemically known as Fe). Non-ferrous then, simply means no iron or only tiny amounts are found in the metal.
Why does it matter if a metal is ferrous or not?
In order to select the best metal for a job, you need to know if it is ferrous or not due to the properties of iron. The presence of iron makes some metals vulnerable to rusting when exposed to air and moisture, so certain uses for them will be limited by these characteristics.
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What is a non-ferrous metal?
As we explain on our ferrous metals page, they contain iron as part of their make-up. Non-ferrous metals do not contain a significant amount of iron in their composition. Non-ferrous alloys generally have iron compositions of less than 1% as measured by weight.
What are the qualities of non-ferrous metals?
It is hard to define the common properties of non-ferrous metals because there is such a variety of metals that fall into the non-ferrous category. However, non-ferrous metals all do have a couple of things in common: They are not magnetic and they do not rust. They can corrode though. This means that non-ferrous metals will never form the red flaky material you see on some steel and iron, because rust is iron oxide and non-ferrous alloys have no significant amount of iron in them.
How are non-ferrous metals used?
Here are some details on the more common non-ferrous metals, but there are many more such as tungsten, titanium, zinc, silver, gold, platinum, and lead.
Without the addition of alloying elements, it is more ductile and not quite as strong as many steels (and far lighter) but can still achieve very high strengths. It forms a protective oxide layer that helps it reduce the risk of corrosion.
Marine equipment, aerospace equipment, construction material such as beams and rails, and certain types of cookware.
In an unalloyed state it is softer, more ductile, and not as strong as carbon steel. Copper can be alloyed with other elements to give it improved mechanical properties. When copper is alloyed with tin it is bronze and when alloyed with significant amounts of zinc, it is brass.
Electrical components such as wires, terminals, and other types of connectors, coating on some currency, pipes for plumbing, tools, and decorative work.
Nickel is another popular non-ferrous alloy. Nickel is known for its toughness, ability to perform in high temperature and low temperature environments, and corrosion resistance. Nickel is not often used in its pure form, and like copper and aluminium, it is often alloyed with other elements to gain superior chemical and mechanical properties.
Cryogenic equipment such as tanks; hot-section aerospace equipment such as combustion chamber components; and marine equipment.
Brass is copper alloyed with a lot of zinc. Adding aluminium improves resistance to corrosion, manganese, iron, tin and aluminium its durability, and lead its machinability. Brass has high thermal and electrical conductivity.
Taps, locks, piping, letter boxes. ornaments and many electrical appliances.