Early Iron Making in America

“Early Iron Making in America” by Lewis discusses the reason iron making began in colonial America and how colonial Americans made iron. In the early colonial days, almost all tools were mad of wood except for parts that needed to be used for cutting or striking. Machines like water wheels, gears, and spinning wheels were also made from wood. However, wood was not the optimal material for these jobs, mainly because wood would easily wear down over time due to friction. Iron could be made in small quantities by the colonists and they used it in cutting tools, kitchen equipment, and weapons. Because they had some experience with iron, the colonists knew it was more durable than wood.

The first way colonists produced iron was through the use of a bloomery. The bloomery was a primitive method of making iron that required very little equipment. The process started with taking chunks of iron ore and heating it in a stone hearth with charcoal and a bellows to circulate air. This would produce a spongy mass of iron that would be hammered and reheated to purify the iron, creating a type of iron known as wrought iron. The wrought iron was very versatile and could be shaped into nearly any tool or weapon. The demand for the skill of working a bloomery was so high compared the supply of people with the skill that bloomery workers in Virginia charged such exorbitant prices for their services that county courts had to regulate prices to a point where iron was affordable.

The biggest limitation of producing iron via a bloomery was the low quantity of iron it was able to produce. The bloomery usually produced enough iron for local blacksmiths, but not enough for the large and expanding market and its high demand for iron. This shift in the market caused a transition from the bloomery to the blast furnace. Unlike the bloomery, the blast furnace was not a simple structure. The blast furnace was 25 to 30 feet tall made from layers of stone and clay. Iron ore was smelted inside using charcoal due to its high burning temperature, limestone was added to remove impurities, and bellows would blow air in through a small hole called a tuyere to further increase the temperature. The liquid iron would then drain down into a part of the furnace called the crucible. Once all the iron had melted, a hole would be unplugged and the iron would flow into sand molds. This iron produced by blast furnaces became known as pig iron because the molds around thee furnace resembled a litter of pigs nursing from a mother sow. Iron from blast furnaces could also be cast into other shapes such as various pots and pans.

Blast Furnace Diagram

For most purposes in the colonial era, wrought iron and pig iron worked just fine. However, a few things such as sword, cutlery, and clock and watch springs needed a stronger alloy, steel. This steel could be created through baking strips of iron and charcoal dust in a clay vessel for up to 11 days. Even after this long process, only the outer layer of the iron would be infused with carbon, so the core of the steel strips would still be iron.

Written by G. Morris. Word count: 537(without header or captions)

10 Replies to “Early Iron Making in America”

  1. Good description about the process of how iron was made. It’s always interesting to read about the origins of the significant technologies (like iron). after reading this, I became curious to see the iron-making process live. I found a video on a group of people who smelted iron in a traditional bloomery: https://www.youtube.com/watch?v=zsywnQJMJEk
    Also, if anyone was curious to know how iron not only impacted the Americas, but other countries as well. This source talks about the Iron Age: https://www.history.com/topics/pre-history/iron-age

  2. Great post Gabriel! Metalworking certainly is an interesting process. Just like in today’s society, the majority of goods produced during the 18th and 19th century either had metal parts or were produced using metal parts. In order to metal to make these parts, iron had to be separated from any contaminants in order to produce the strongest result. As Lewis states, blacksmiths first employed the use of the bloomery, which was relatively effective, but did not produce well-purified iron. The blast furnace, while more expensive, produced much more iron of a higher quality and at a faster rate. This technology really began to open up the metalworking industry, resulting in cheaper, stronger iron and therefore cheaper, higher-quality products.

  3. Gabriel,

    I really liked your summary of the Lewis article; easy to understand while covering the high points. I was surprised that the origin of the name pig iron was so literal – it looked like pigs, so that’s what it was called. The article below offers more information on pig iron production and the science behind it, as well as some videos on the subject.

    https://www.metallics.org/pig-iron-bf.html

  4. Great post, your examination of the evolution of iron working in American is excellent, I just wonder how these methods compared to the new country’s European counterparts at the time. I also like how you provided imagery of blast furnaces for context and discussed the limitations of bloomeries in America. I also thought it was interesting how simple the process of simply melting out the iron from the ore and separating it from the slag was. Heres an article on more http://www.revolutionarywarjournal.com/iron-forge-in-colonial-america/
    Nathaniel Dekin

  5. Great summary of the article! I enjoyed how you described the different ways iron was made in a way that is easy to understand. Also, the image you included is helpful in understanding how iron is produced. I also found it interesting how much technological advancement can have on the cost of the final product. For example, the blast furnace was more expensive in the beginning, but over time, it led to cheaper production of iron, and thereby cheaper products.

  6. This post was very interesting to read. It was a nice summary of how and why iron was used in these times. The diagram was good, as it showed the parts of the blast furnace, which allowed me to understand how it works. It was also neat to make the connection to the slides in class, which discussed the same topic. Great job.

  7. Gabriel,

    I particularly enjoy this subject matter, and I think you do an excellent job detailing it, leaving me very impressed with this post.

    Great job using images to further your synopsis of this article.

  8. Good work capturing the highlights of the article. I have always found metallurgy interesting as a profession and learning about its roots was definitely a good highlight. Finding out the simplicity of bloomeries makes me want to construct one at home and perform my own metallurgy work.

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