The terminology surrounding iron and steel has remained largely unchanged for decades, despite significant advancements in materials and processes. This has led to widespread misconceptions. As a blacksmith, I frequently receive requests for wrought iron pieces or have clients show me photos of cast iron items they’d like replicated. Because of this, I often find myself explaining the differences to ensure their needs are met. I’ve had this conversation so many times that I decided to write a short blog post on the topic.

To understand how these terms apply to any finished product, we need to consider two key elements: process and material.

  • Process refers to how the material is manipulated—both in its initial formation and in its shaping into a functional object.
  • Material refers to the chemical composition of the metal itself.

Breaking Down the Terminology

Iron

Iron is an element on the periodic table, but pure iron is virtually nonexistent in practical applications outside of chemistry. On its own, iron lacks the strength of mild or stainless steel.

Mild Steel 

Mild Steel is iron with .05-.25% carbon added, which improves strength and hardness. A36 mild steel is one of the most common; used in ornamental, fabrication, and forging applications.

Wrought Iron

The term wrought means “worked,” referring to the process of shaping an iron bloom into a usable material. Wrought iron is an iron alloy with very low carbon content (less than 0.05%), making it more malleable and corrosion-resistant. However, it is rarely used today, having been largely replaced by mild steel.

Cast Iron

Cast iron is an alloy containing 2% to 4% carbon, along with varying amounts of silicon, manganese, and trace impurities such as sulfur and phosphorus. The term cast refers to the process of heating the iron alloy to a molten state and pouring it into a mold, resulting in a rigid, brittle material often used for cookware and architectural elements.

Forged Iron

Most forged products today are made from mild steel, which is more readily available and stronger than traditional iron. Forging is the process of heating metal to a workable temperature (900–1200°F) and shaping it using a hammer and anvil. This process enhances the strength and durability of the final product.

Understanding Modern Usage

In today’s world, when you purchase a “wrought iron” fence, it is likely made of mild steel. Similarly, a “forged iron” pan is probably made of mild or stainless steel. While these terms are often used incorrectly, they have evolved to describe an overall aesthetic rather than the actual material.

For instance, cast products typically have a rough, grainy texture that some find appealing, while forged pieces can showcase a variety of textures depending on the refinement and technique used.

By understanding the true meanings behind these terms, clients can better communicate their needs and expectations when commissioning custom metalwork. Luckily, many various textures can be achieved with different forging techniques. At Element Hand Forged Hardware, we’ve replicated hundreds of elements made from varying materials and processes. Whether you’re looking to replicate hundred year old hardware or a modern fabricated piece, we’ve got you covered. Reach out today to discuss your project!