How Cast Iron Is Made – Step By Step

cast iron pan on a table

As you might know, I love cast iron grill grates but never knew how cast iron is made. Time to find out!

What Is Cast Iron?

Cast iron (1) is made up of a reasonable number of iron alloys but is mostly linked to Gray irons. Even when they are all called ‘iron’, it cannot be said to be an “elemental iron”.

They (iron cast) are just another alloy that contains the same carbon properties, in addition to a very small amount of manganese and silicon.

Cast iron will always fracture when subjected to any form of stress, so it is considered non-malleable and very hard.

By saying ‘not malleable’ we mean it (cast iron) cannot be altered or shaped, be it through hammering, bending, or stretching. So, be careful with your cast iron Hibachi grills.

Cast Iron Manufacturing Process

They (cast irons) are formed using either melting pig iron (which is a product formed from iron ore extraction) or smelting iron ore. These two elements are mixed with the combination of other metals and scrap metals as well. The mixture is gently poured into molds, then given some time to cool down.

A video can make it a lot easier to understand than my writing.

YouTube video player

How long it takes it to cool down is not exact, it depends on the quantity and the rate at which it is heated. 

When heated at 1,000 degrees, it can take up to approximately 6 weeks to cool down, then solidify. The outcome of this will be a strong, yet brittle iron metal.

Because of the presence of high carbon properties, cast irons tend to solidify, just as you will experience in other different alloys.

The smaller structures of cast iron give it the typical physical properties it adorns. Internal carbon particles in cast irons create inward stress points which play a big role when especially when the iron experiences fracture.

Finally, it is important to note that the various heat processes in the production of cast iron are what make it stand out from its counterparts

cast iron skillet

Enameled Cast Iron

I love my enameled and ceramic-coated grill grates. I found a video about how that is made also. I thought it was interesting.

YouTube video player

Cast Iron History

The production of cast iron has been traced back to 6th century BC China, and the 14th-century European industrial era.

The art was introduced in England in the 15th century before finding its way to America in the 16th century hence, the establishment of the first known ironworks in 1619 at James River, Virginia.

But towards the middle of the 18th century down to the 19th century, cast iron overtook wrought iron because it was said to be a cheaper engineering material than wrought irons, thus, the increased production rate throughout Europe and America, and its brittle nature too.

What Is Cast Iron Composed Of

The phosphorus in iron cast increases the smooth (and elegant) structure in cast irons, but when it contains over 0.30%, it often ends up lacking workability and toughness.

The silicon content is mixed with some parts of iron to form a strong, solid solution – carbons are also removed from its graphite form. Iron Cast reduces its ability to shrink and guarantees a softer and more durable casting when it is less than 2.50%.

While the sulfur content in cast irons makes it hard and inflexible, it doesn’t allow cooling in a sand mold. The presence of sulfur results in fast solidification of the cast iron causing sand and blowholes. Moreover, the standard presence of sulfur in an iron cast should be maintained below 0.10%.

Cast Iron – My Opinion

As I mentioned several times I think cast iron grill grates are great in my opinion.

They retain the heat very well and although it takes a little longer to heat up they make the best grill marks I think.

The bad thing is that it is pretty heavy and if you drop it it will break easily.

I love cooking in my Dutch Oven and believe that the dishes I cook in there would not turn out the same if cooked in a pan of a different material.

Cast iron is also used in most of the so-called over the fire cooking because of the heat retention and durability.

There are many opinions about cast iron that are not true so I also wrote an article that does bust a lot of cast iron myths for your information.

Feel free to share your opinion in the comment.

Eddie van Aken

Eddie van Aken has years of experience in running his full-service restaurant and with this came working with using and dealing with all types of kitchen equipment. With his experience, he can find all the pros and cons of grills and add them to the grill reviews he is doing. You can read more on the about page for Eddie van Aken

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