October 2021

Steel is everywhere. Look around.

Buildings. Bridges. Safety rails. Brackets. Cars. Trains. Sinks. Surgical tools. Jewelry. Even the scissors in your kitchen drawer.

It’s one of the most widely used materials on the planet, yet few people ever stop to ask the obvious question — where does steel actually come from?

Let’s walk through it.

Step 1: Turn Raw Materials into Molten Metal

It starts with iron ore, mined from the ground.

But iron ore on its own isn’t enough. It needs to be reduced, and that’s where coke comes in. Coke is created by crushing coal, then carburizing it at high temperatures in a furnace without oxygen. What you get is a carbon-rich, rock-like material that looks like small black chunks.

Add the coke, the iron ore, and some limestone to a blast furnace. That’s where the transformation happens.

Superheated air is blown into the base of the furnace, igniting a combustion reaction. The result? Molten pig iron. (Fun fact: it takes about 1.5 tons of iron ore to make just 1 ton of steel.)

The limestone helps remove impurities like silicon dioxide — the stuff you’d find in sand and rock.

Technically, pig iron isn’t quite iron or steel. But it’s the bridge between the two.

Step 2: Convert Pig Iron to Steel

Once the pig iron is molten, it’s transferred by ladle to another furnace.

There, it’s combined with scrap steel in one of two systems:

Basic oxygen furnaces, which blast high-pressure oxygen into the metal to burn off impurities
Electric arc furnaces (EAFs), which melt scrap instead of ore — a more sustainable method, though it can yield lower-grade steel

By this point, the transformation is complete. Molten steel is born.

Step 3: Shape It with Continuous Casting

Ladles transfer the molten steel into tundishes, which feed into a continuous caster.

The caster shapes the metal as it cools, forming it into things like:

Ingots
Blooms
Billets
Slabs

These are all known as semi-finished products — not ready for use, but ready for what comes next.

Step 4: Roll It Out

Next, the steel passes through rolling mills, where it’s processed into usable forms:

Steel plates
Coils
Rods
Bars

If the steel is rolled while hot, it’s called hot rolled steel. If it’s done after cooling, you get cold rolled steel, which is stronger and has a smoother finish.

Step 5: Final Touches

The last step is finishing.

Depending on the end use, that might include:

Pickling
Coating
Tinning
Annealing
Tempering
Cutting
Slitting
Coiling
Packing

Each of these changes the performance or appearance of the steel before it heads off to do its job in the world.

Want to see how it all works? Check out this video and article from the American Iron and Steel Institute.

Bonus Resources

If this kind of thing sparks your interest, FlexTrades has a whole archive of How It’s Made content. It’s worth the scroll.

Manufacturing has evolved through four industrial revolutions, and with each shift, machines have played a central role in shaping how things get made. Among them, the metal working mill has quietly remained a constant.

It doesn’t get as much historical attention as the lathe, but the mill has earned its place — not just in factories, but in the foundation of modern production itself.

Eli Whitney and the Birth of the Mill

The story of the mill begins in the late 1700s, when clockmakers used crude versions to cut balance wheels. But it wasn’t until 1818 that the United States could truly call the milling machine its own. That credit goes to Eli Whitney.

You probably know Whitney as the inventor of the cotton gin. What you might not know is what came next.

Facing the threat of war with France, the U.S. government began offering contracts for mass musket production. At the time, muskets were handmade, and that meant each one was slightly different. No interchangeable parts. No inventory system. No consistency. Whitney saw the flaw. And he saw the fix.

He began designing machine tools that could create musket components with identical size, shape, and function. These tools would allow parts to be mass-produced, stored, and swapped. That vision led to the milling machine — and, more importantly, to the production system we still rely on today.

In 1801, he presented this system to President-elect Thomas Jefferson. Jefferson was impressed. And with that vote of confidence, Whitney began manufacturing arms with his new technology, eventually passing the business to his son in Hamden, Connecticut.

Evolution Through the Revolutions

Milling machines didn’t stop evolving with Eli Whitney.

In 1867, American engineer Joseph R. Brown debuted a universal milling machine at the Paris Exhibition. It was a leap forward in precision and capability. Then in 1936, Rudolph Bannow improved the design even further. He believed mills should offer more movement and access — allowing tools to approach a part from multiple angles with less manual repositioning.

Bannow’s invention became the Bridgeport milling machine. It was revolutionary. And even now, many U.S. manufacturers still use Bridgeports in their shops.

But as game-changing as the Bridgeport was, it’s still manual. And with the rise of automation, software, and digital control systems, milling machines have taken another leap — this time into CNC.

But that’s a story for another day.

FlexTrades exists to solve problems for American manufacturers. That’s our purpose. But solving real problems means asking hard questions. And sometimes, answering them.

One of the questions we hear most often from job seekers and clients alike is this:

What is ITAR, and why should I care?

Let’s break it down.

Understanding ITAR

ITAR stands for International Traffic in Arms Regulations. These are federal laws enforced by the U.S. government. They exist to protect national security by controlling who has access to defense-related products, data, and services.

If you build, supply, or support anything tied to military use — directly or indirectly — you’re in ITAR territory. That includes primary manufacturers, vendors, and even subcontractors in the supply chain.

Being ITAR compliant isn’t just a title. It means implementing safeguards to restrict access to sensitive materials and systems. It means following strict rules to prevent foreign nationals from accessing defense-related information. It means recertifying every year.

And if your company operates across borders? It means navigating some serious complexity — across documentation, digital access, hiring practices, and more.

What ITAR Means for Job Seekers

If you’re applying for a position at an ITAR-compliant company, there’s one thing you’ll need: proof of ITAR eligibility.

That usually includes two forms of government-issued ID, with at least one containing your photo. Requirements vary, but the company will tell you exactly what to provide. If you’re curious, here’s an example list of acceptable documents used for defense conference access.

This isn’t red tape. It’s law. And it’s important.

Still Curious About ITAR?

Want a deeper dive? The U.S. government offers detailed guidance on ITAR — who it applies to, what it regulates, and how compliance is maintained.

And if you’re new to the FlexTrades blog, stick around. We’ve got more answers where this came from.

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Got a Question of Your Own?

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