What Is The Melting Point of Iron? Temp, Colour & Properties

Iron is the most common element on Earth, even more than oxygen. It’s found mostly in the Earth’s crust, which is extracted and used in a huge variety of ways, including for weapons, bridges, and buildings across the world.

For iron to be turned into something useful, it must first be melted. Once melted the element becomes ductile and easy to manipulate, when blacksmiths and metalworkers mould it into the desired shapes.

Iron is the most common element on Earth, even more than oxygen. It’s found mostly in the Earth’s crust, which is extracted and used in a huge variety of ways, including for weapons, bridges, and buildings across the world.

For iron to be turned into something useful, it must first be melted. Once melted the element becomes ductile and easy to manipulate, when blacksmiths and metalworkers mould it into the desired shapes.

The melting point of iron is 1,583°C (2800°F). When the science of metallurgy was first developed around 1200 BC by the Anatolian (modern day Turkish) Hittites, they smelted their “black rocks that melt” using small ceramic crucibles. Today, blacksmiths and metalworkers melt iron using forges that are fueled by propane, gas, coal, or charcoal. Once melted, they shape the iron using tools like hammers, anvils, and chisels.

Colour is a good indicator of the temperature of iron, and how much it is melted. It goes through a variety of colours as it heats up: red, orange, yellow, and then white. The best heat for forging is usually in between orange and yellow, when the material is particularly bright. This is called “forging heat.”

While commonly confused, melting and smelting are two different processes with unique goals. Iron is melted to manipulate it into useful things, and smelting is a way to extract a base metal from an ore, such as silver or copper. Smelting is often used to produce pig iron which can then be converted into much more useful steel.

Iron is an odd chemical because of how its atoms arrange themselves when heat is applied. At regular room temperature, its atoms are in a loosely packed open arrangement. When heat is applied past 912°C, the atoms become even more closely packed, which is a strange occurrence. When 1,394°C is reached, the atoms loosen again, and then finally melt when the temperature hits 1,538°C.1 This quirkiness of iron is one of the reasons why steel is so strong and sturdy.

Steel is an iron alloy that is also used in a huge variety of ways, including for tools, cars, and other machines. The melting point of steel is between 1,371 to 1,537°C (2,500 to 2,800°F). As an alloy of iron and carbon, the “impurity” of carbon in the iron is what causes the lower melting temperature. This occurs for any material that has an impurity because the added chemical disrupts the bonding arrangement and makes the substance less energetically favourable, making it easier to melt.

Chemical and atomic properties of iron

References

1. Jessica Stoller-Conrad, 2015, Why melting iron is such a weird process, Futurity