What are the Differences Between Ferrous and Non-Ferrous Metals?
The basic difference between Ferrous and non-ferrous metals is that ferrous metal or alloys contain iron and are attracted to magnetic field, while non-ferrous metals do not contain iron and are not attracted to magnets.
Further, Ferrous metals are harder and stronger than non-ferrous metals, but they are also more susceptible to rusting (corrosion). Non-ferrous metals are more malleable than ferrous metals, which means they can be easily shaped and molded.
We can simply say that the Ferrous metals are those that contain iron and non-ferrous metals are those that do not.
Here are top 10 differences between the Ferrous and Non-Ferrous Metal:
- Ferrous metals are magnetic while non-ferrous metals are not.
- Ferrous metals rust when exposed to air and moisture, while non-ferrous metals do not. Ferrous metals are less corrosion-resistant than non-ferrous metals, however, they can be protected with a coating of paint or other corrosion-resistant material.
- Ferrous metals are harder than non-ferrous metals.
- Ferrous metals are heavier than non-ferrous metals.
- Non-ferrous metals are better conductors of heat and electricity than ferrous metals.
- Non-ferrous metals are less likely to corrode than ferrous metals.
- Non-ferrous metals generally have a higher melting point than ferrous metals.
- Non-ferrous metals are more malleable, meaning they can be easily hammered or pressed into shape.
- Non-ferrous metals are generally more expensive than ferrous metals due to their rarity.
- Both ferrous and non-ferrous metals are of engineering uses.
Ferrous vs Non-Ferrous Metals
There are two main types of metals: Ferrous and non-ferrous metals. Ferrous metals contain iron, while non-ferrous metals do not. Both ferrous and non-ferrous metals have their own unique properties and uses.
| Features | Ferrous Metal | Non-Ferrous Metals |
|---|---|---|
| Cost | ✅ Cheaper | ⛔ Costly |
| Corrosion resistance | ⛔ Inferior | ✅ Superior |
| Magnetic | ✅Yes |
⛔ No |
| Hardness | ⛔High | ✅ Low |
| Melting Point | ✅ Low | ⛔ High |
| Malleability | ⛔ Inferior | ✅ Superior |
| Density (mostly) | ⛔ High | ✅ Low |
| Electric conductor | ⛔ Poor | ✅ Good |
| Heat Conductor | ⛔ Poor | ✅ Good |
| Contains Iron | Yes | No |
| Does not rust | ⛔ No | ✅ Yes |
| Strength (mostly) | ✅ High | ⛔ Low |
| Examples: | Steel, Cast Iron, mild steel | Copper, Aluminum, Brass |
Ferrous metals are strong and durable, making them ideal for use in construction and manufacturing. They are also magnetic, which makes them useful in a variety of applications.
However, ferrous metals are also susceptible to rusting, so they must be properly cared for to avoid this problem.
Non-ferrous metals are not as strong as ferrous metals, but they are more resistant to corrosion. This makes them ideal for use in environments where corrosion is a concern, such as salt water or acidic conditions.
Which Metals Are Ferrous?
From the beginning of civilization, man is in the search of newer and newer materials. Gold, silver, and copper are known to man from the Stone Age when the ancient people used to kill their prey with the help of stone weapons.
Iron is being used for more than the last 8000 years when the iron tools were chipped from the pieces of meteorites containing metallic iron. Initially, iron was used in the forged form, and then iron casting was established.
There are two types of alloys:
- Ferrous alloys and
- Non-ferrous alloys.
In ferrous alloys, iron is the prime constituent and for the improvement of its mechanical and physical properties, various elements such as Ni, Cr, Mn, and W are added.
Plain Carbon Steel
There are different types of plain carbon steels depending upon the carbon percentage and the majority of the materials used in the engineering industry are plain carbon steels.
About 90 percent of the total steel production is of plain carbon steels used in various forms and various applications in the form of wires, wire products, tubular products, sheets, strips, cast and forged parts, and cutting tools.
Plain carbon steels are divided into various categories as follows:
- Low-carbon steel (C< 0.25 percent) or also called Mild steel,
- Medium-carbon steel (C0.25-0.60 percent),
- High-carbon steel (C> 0.60 percent),
- Hypoeutectoid steel (C< 0.80 percent),
- Eutectoid steel (C = 0.80 percent),
- Hypereutectoid steel (C> 0.8 percent)
Stainless Steel
All stainless steel including ferritic, austenitic, martensitic and precipitation hardened are ferrous alloys. Examples are SS304, SS321, SS410, 17-4PH, etc.
To learn about what is Stainless Steel and their types, check out my article on What is Stainless Steel?
Cast Iron
Cast Iron contains predominately Iron and hence is the commonly used Ferrous alloy. There are different types of cast irons such as grey cast iron, white cast iron, malleable cast iron- all of these are ferrous.
Which Metals Are Non-Ferrous?
In non-ferrous alloys, the prime constituent is not iron but other elements like Cu, Ni, Ti, Al, Mg, and so on. In non-ferrous alloys, the prime metal is non-ferrous such as copper, aluminum, nickel, and zinc.
To read more about most important engineering metals and non-metals read my article on Types of Metals and their properties.
Non-ferrous alloys are classified on the basis of this prime metal used such as copper-base, aluminum-base, and nickel-base alloys. Then, there are wrought and cast alloys, as well as heat-treatable and non-heat-treatable alloys.
Under non-ferrous alloys, there are cast and wrought alloys and heat-treatable and non-heat-treatable alloys.
Limitation of Ferrous Metals
Although ferrous alloys are produced abundantly and are used in large quantities, there are certain inherent disadvantages to using them when we compare ferrous and non-ferrous metals:
- High density, while for aerospace applications low density is the basic requirement,
- Low electrical conductivity, while in many electrical applications high electrical conductivity is of prime concern and
- Susceptibility to corrosion and in many applications in atmospheric environments, alloys with good corrosion resistance are the main requirement.
Types of Ferrous Metals
In ferrous alloys, iron is the prime constituent; as in plain carbon steels, carbon varies from 0 to 1.4 percent and the rest is iron as explained earlier in this article.
Ferrous alloys are produced in much larger quantities than any other metal alloys. The majority of engineering components are made from ferrous alloys as plain carbon steels, cast irons and alloy steels.
There are three main factors for the use of ferrous alloys:
- iron ore exists in abundance in the Earth’s crest,
- extraction of iron from ores and manufacture of steel and cast irons are economical and
- iron alloys are extremely versatile and can be made as per the requirements of mechanical and physical properties.
However, ferrous alloys are susceptible to corrosion and oxidation. For the protection from corrosion, alloying elements such as chromium and nickel are added to produce stainless steels. Special-purpose steels are developed for specific requirements like:
- high-temperature application e.g., for boilers & power plants,
- Cryogenic temperature applications for storage of liquefied gases,
- application in measuring instruments and steel with minimum coefficient of thermal expansion (in pressure gauges) and
- High-speed cutting tools such as HSS.
