Cast Iron Vs. Steel: The Comparison

You may have heard that cast iron and steel are different, but you're not sure what the difference is. Cast iron and steel are often compared as two of the most commonly used metals in industry. There are many differences between them.
cast iron VS. steel

Cast iron vs. steel, which one is better in CNC machining? When it comes to CNC machining, the choice of material can make a big difference in the outcome of your project. Two options are cast iron and steel, each with its own unique properties and advantages.

In this blog post, we’ll take a closer look at the differences between cast iron and steel in CNC machining. We’ll compare their strength, durability, machinability, and other factors to help you decide which material is best for your specific needs.

So, whether you’re a seasoned machinist or just starting out, read on to learn more about the comparison between cast iron and steel in CNC machining.

Cast Iron vs. steel: Chemical Composition

The main difference between steel and cast iron is their carbon content. Iron is an element, whereas steel is just a by-product of iron. 

Cast iron contains more than 2 percent carbon, whereas plain steel only has 0.1-0.5 percent. You might know that the higher the carbon content, the more malleable iron will be.

Cast Iron Vs. Carbon Steels

Cast IronCarbon Steels
Material TypesGrayWhiteDuctileLow-CarbonMedium-CarbonHigh-Carbon

Cast Iron Vs. steel: Mechanical Properties

Melting Point

The melting point of a substance is the temperature at which it changes from a solid to a liquid. The melting point of steel is higher than the melting point of cast iron.

This means cast iron can be melted and cast into shapes more easily than steel. It also means that cast iron is more susceptible to damage from heat. When exposed to high temperatures, cast iron can warp and crumble.


Those who have ever worked with metal know that different types of metal have different properties.

One key difference between different types of metal is fluidity, which refers to a metal’s ability to flow. 

Steel has little fluidity, making it difficult to shape into desired shapes. In contrast, cast iron has excellent fluidity and can be easily molded into various shapes.

Corrosion Resistance

Despite being one of the oldest engineering materials, cast iron is still widely suitable for various applications. One of the best reasons for its popularity is its excellent corrosion resistance.

Cast iron is more resistant to corrosion than steel. This is due to several aspects, including the higher carbon content of cast iron and the formation of a protective oxide layer on the surface of the metal.

And cast iron typically contains impurities that enhance its corrosion resistance, such as chromium and nickel.

Impact Resistance 

Steel is much more robust than cast iron and is thus more impact-resistant.

When a force is applied to steel, it will deform before it breaks. This means that it can withstand much more force before failing. In contrast, cast iron is brittle and will break under relatively little force.

Vibration Absorption

Cast iron has many valuable properties that make it ideal for various applications. The most remarkable characteristic of cast iron is its ability to absorb vibrations and noises.

This makes it an ideal choice for use in industries with a lot of machinery and equipment, as it can help create a more peaceful work environment.

Cast Iron Vs. steel: Advantages And Disadvantages 

Cast Iron

While cast iron has declined in popularity recently, it remains an excellent material for many applications.

One advantage of cast iron is its strength. It is significantly stronger than other materials, such as aluminum, making it ideal for construction and heavy industry.

Cast iron is resistant to wear and tear, meaning it can withstand much use without requiring frequent replacement. Cast iron is relatively easy to produce, making it a more affordable option than some other materials.

There are also some disadvantages to using cast iron. It is a very brittle material, making it susceptible to breaking or shattering under stress.


Steel is an alloy of carbon and iron, one of the essential materials in modern industry. It has numerous advantages over other materials, including a high strength-to-weight ratio, good durability, and easy recyclability. Steel has more tensile strength than cast Iron.

And steel also has several disadvantages, such as a high production cost and a relatively high density. Steel is sometimes replaced by other materials, such as aluminum or composites, for specific applications with less significant advantages. We can CNC machine steel parts.

Cast Iron Vs. steel: Application Field

Steel and cast iron are two of the most critical metals in the world. They both have unique properties that make them essential for a variety of applications.

When it comes to resistance, steel is the better option. It is more resistant to impact and wear, lasting longer in heavy-use situations. Steel is also less likely to break or deform under stress, making it the safer choice for many construction projects.

Cast iron is a type of metal used for centuries for various purposes. It has a high melting point and resistance to wear and tear, making it an ideal material for many applications.

Today, cast iron is often suitable for producing cookware, as it can evenly distribute heat and sear food effectively. It is also mainly suitable for constructing buildings and bridges, as its strength and durability make it an excellent material for these structures.

Machining Capability

Cast iron and steel parts are essential for many industrial and commercial applications. They need to be of the highest quality to function as intended. Our team has the expertise to produce cast iron and steel parts that meet your specifications. We have a rigorous quality control process in place that ensures all parts meet our high standards. Let us help you with your next project.

cnc machining capability


What Is Cast Iron?

Cast iron is a common alloy of iron and carbon that has been melted and poured into a mold. It is a durable metal often used in manufacturing pipes, cookware, and machine parts. And cast iron is cheaper.

Cast iron is made by heating iron ore in a furnace until it becomes molten. The hot liquid iron is then poured into molds, where it cools and solidifies. The resulting metal is hard and brittle but can be cast into different shapes.

Because of its strength and versatility, cast iron has been used for centuries in various applications. Today, it remains an essential material in the construction and manufacturing industries.

What Is Steel?

Steel is an alloy of carbon and iron, containing between 0.2% and 2.14% of carbon by weight. Depending on the amount of carbon content, steel can be classified as low-carbon, medium-carbon, high-carbon, or very high-carbon steel. Cast iron has more compressive strength, and steel is more tensile.

Steel is one of the most ordinary materials daily, with more than 1.3 billion tons produced yearly. It suits various applications, including construction, machinery, and transportation.

Steel has a long history dating back to prehistoric times when it was first used to make tools and weapons. Today, it remains an essential material in our lives.


Steel and cast iron are the most popular materials in machining metal parts. Each material has unique benefits and drawbacks, which we’ve outlined in this article. We have strong CNC machining capabilities.

If you’re still unsure about which type of metal to choose for your next project, visit our company homepage to learn more about our products and services. We would happily help you find the perfect material for your needs.

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