What Material Was the Eiffel Tower Made From?

Understanding the Iron Behind the Icon

More Than Just “Metal”

When most people look at the Eiffel Tower, they simply think:

👉 “It’s made of steel.”

But that’s not actually correct.

The Eiffel Tower was built using a material that predates modern structural steel — a material that played a crucial role in 19th-century engineering:

👉 Wrought iron.

Understanding what the Eiffel Tower is made from isn’t just a trivia fact — it reveals how engineers of the time were able to design, fabricate, and assemble one of the most iconic structures in history.

The Primary Material: Wrought Iron

The Eiffel Tower is made from:

👉 Puddled wrought iron

This is a refined form of iron that was widely used before modern steel became dominant.

Key facts about the material:

• The tower consists of 18,038 individual iron components

• The total weight of the iron structure is approximately 7,300 tons

• All pieces were prefabricated and assembled on site

Wrought iron was chosen because of its unique properties, which made it ideal for large-scale structures at the time.

What Is Wrought Iron?

Wrought iron is a type of iron that has been:

• Heated and worked repeatedly

• Refined to remove impurities

• Strengthened through mechanical processing

The term “wrought” literally means:

👉 “worked”

Unlike cast iron (which is brittle), wrought iron is:

✔️ Tough

✔️ Ductile (can deform without breaking)

✔️ Resistant to fatigue

These properties made it perfect for structures that needed to handle:

• Dynamic loads

• Wind forces

• Thermal expansion

Why Wrought Iron Was Used Instead of Steel

Today, steel is the standard material for construction. But in the 1880s, when the Eiffel Tower was built, steel production was still developing.

At the time:

• Steel was expensive and less consistent in quality

• Production methods were still evolving

• Large-scale structural use was limited

Wrought iron, on the other hand:

✔️ Had a proven track record

✔️ Was easier to produce reliably

✔️ Was well understood by engineers

👉 It was the best available material for a project of this scale.

The Source of the Iron

The iron used for the Eiffel Tower came primarily from:

👉 The Pompey ironworks in France

This ensured:

• Consistent material quality

• Reliable supply

• Standardised fabrication

Each piece of iron was manufactured according to detailed engineering drawings before being transported to the site.

Prefabrication: The Real Secret Behind the Material

One of the most important aspects of the Eiffel Tower’s construction was not just the material itself — but how it was used.

👉 Every iron component was prefabricated.

What this means:

• Pieces were manufactured off-site

• Each element was cut, shaped, and drilled precisely

• Components arrived ready for assembly

This approach allowed for:

✔️ Faster construction

✔️ Higher accuracy

✔️ Better quality control

This is the same principle used in modern steel construction today.

How the Iron Components Were Connected

The iron components were not welded or bolted as we would expect today.

Instead, they were connected using:

👉 Rivets

More than 2.5 million rivets were used in the construction.

The process involved:

1. Heating the rivet until red-hot

2. Inserting it into aligned holes

3. Hammering the end to form a second head

4. Allowing it to cool and contract

As the rivet cooled:

👉 It tightened the joint, creating a very strong connection.

How the Material Handles Environmental Forces

Wrought iron gave the Eiffel Tower several important advantages.

1. Flexibility Under Wind Load

The tower can sway slightly in strong winds.

👉 This flexibility prevents structural damage.

2. Resistance to Fatigue

Repeated loading from wind and temperature changes does not easily weaken wrought iron.

3. Thermal Expansion Capability

Iron expands when heated and contracts when cooled.

The Eiffel Tower can grow or shrink by several centimeters depending on temperature.

The Role of Protective Coatings

Iron is strong — but it has one major weakness:

👉 Corrosion (rust)

To protect the structure, the Eiffel Tower is:

• Repainted approximately every 7 years

• Covered with multiple protective layers

• Maintained continuously

This prevents moisture from reaching the iron.

Wrought Iron vs Modern Structural Steel

Key Differences

Property	Wrought Iron	Modern Steel
Strength	Moderate	High
Ductility	High	High
Consistency	Variable	Highly consistent
Production	Labour-intensive	Industrial mass production

If built today:

• The structure would use high-strength structural steel

• Components would be fabricated using CNC machinery

• Welding and bolting would replace riveting

READ MORE: Could the Eiffel Tower Be Built Today?

Why the Material Choice Was So Important

The success of the Eiffel Tower depended heavily on choosing the right material.

Wrought iron allowed engineers to:

• Create lightweight yet strong components

• Design intricate lattice structures

• Build at a scale never seen before

👉 Without this material, the Eiffel Tower may not have been possible at the time.

Key Takeaways

• The Eiffel Tower is made of puddled wrought iron, not steel

• Over 18,000 prefabricated components were used

• The structure is held together by over 2.5 million rivets

• Wrought iron provided flexibility, strength, and durability

• Regular maintenance protects the iron from corrosion

The Material That Made History Possible

The Eiffel Tower is not just an architectural landmark — it is a material story.

It represents a time when wrought iron was at the peak of engineering innovation, and when careful material selection made extraordinary structures possible.

More than a century later, the tower still stands as proof that:

👉 Choosing the right material is just as important as the design itself.