Carbon steel is a versatile and essential material that plays a key role in many different industries. It is widely used in construction, manufacturing, automotive, and more. The properties of carbon steel make it a top choice for many applications. But what are the top 5 carbon steel properties?

That’s what we’ll be exploring in this blog post. Read on for the top 5 carbon steel properties and to learn how they impact different grades of carbon steel, from low-carbon steel to high-carbon steel.

1 – Carbon Content

One of the most defining characteristics of carbon steel is its carbon content. The carbon content determines the steel’s hardness, strength, and other crucial properties. Steel is essentially an alloy of iron and carbon, and the amount of carbon present distinguishes one grade from another.

Low-Carbon Steel

This type of carbon steel has a low carbon content, typically between 0.05% and 0.25%. It is known for its ductility and malleability, making it suitable for applications such as machinery, welding, and construction.

Medium-Carbon Steel

Medium-carbon steel contains a moderate amount of carbon, ranging from 0.3% to 0.6%. It strikes a balance between strength and ductility, making it ideal for products like axles, gears, and coil springs.

High-Carbon Steel

With a carbon content of around 0.6% to 1.0%, high-carbon steel is the hardest among carbon steels. It is often used for applications that require sharpness and durability, such as knife blades and bollards.

Ultra-High Carbon Steel

Ultra-high carbon steel boasts a carbon content of over 1.0%. Its exceptional hardness and strength make it suitable for specialised tools like chisels and drill bits.

2. Steel Properties and Alloying Elements

While carbon content is a primary factor, carbon steel’s properties are also influenced by other alloying elements. Some of these elements include chromium, which enhances corrosion resistance, and manganese, which improves tensile strength.

The addition of chromium gives rise to stainless steel, a highly corrosion-resistant variant of carbon steel. Stainless steel is used in the manufacturing of cutlery, kitchen sinks, and various industrial applications. Manganese is often added to improve the steel’s strength and toughness. It’s a common element in medium-carbon and high-carbon steels.

3. Steel Properties and Heat Treatment

The process of heat treatment has a profound impact on carbon steel properties. Heat treatment involves heating the steel to a specific temperature and then cooling it in a controlled manner. This process can enhance a steel’s hardness, toughness, and overall performance.

Annealing involves heating the steel to a specific temperature and slowly cooling it. This process relieves internal stresses and makes the steel softer and more ductile. It is commonly used in the manufacturing of coils, sheets, and high-strength wires.

Quenching and tempering is a two-step process. First, the steel is heated to a high temperature and then rapidly cooled (quenched). This increases the steel’s hardness. Afterwards, the steel is tempered by heating it to a lower temperature, which imparts toughness.

4. Steel Properties and Microstructure

The microstructure of carbon steel plays a crucial role in its properties. Different cooling rates and alloying elements influence the formation of various microstructures in steel. The two primary types of microstructures in carbon steel are ferrite and cementite.

Ferrite is a relatively soft and ductile microstructure. It is found in low-carbon and low-alloy steels, making them suitable for applications that require formability and weldability. Cementite is a hard and brittle microstructure. It is prevalent in high-carbon and high-alloy steels, contributing to their hardness and wear resistance.

5. Steel Properties and Industrial Applications

Now that we’ve covered some of the essential properties of carbon steel, let’s explore how these properties are put to practical use in various industries.

Automotive Industry

Carbon steel is used in the production of vehicle parts, such as axles and gears, due to its strength and durability. It also plays a vital role in chassis and body components.


Low-carbon and medium-carbon steels are commonly used in the construction industry. Their ductility and ease of fabrication make them ideal for structural applications, reinforcing bars, and bolts. Carbon steel is a strong metal for architecture.


High-carbon steel is utilised in the manufacturing of cutting tools, knives, and industrial machinery components. Its hardness and sharpness make it an excellent choice for these applications.

Oil and Gas

High-strength low-alloy (HSLA) steel is used in the oil and gas industry for pipelines, drilling equipment, and storage tanks. It offers the necessary strength and is resistant to corrosion for these demanding applications.


The aerospace industry relies on high-strength carbon steels for aircraft components. These steels provide the required strength-to-weight ratio and are used in landing gear, fasteners, and other critical parts.

Steel Fabrication at Astra Engineering

From low-carbon steel used in construction to high-carbon steel in knife manufacturing, understanding the mechanical properties of carbon steel is crucial for selecting the right material for the job.

At Astra Engineering, we are fabrication experts. Because of carbon steel’s versatility and adaptability, we use this metal frequently in our fabrication projects. From mild steel to higher-carbon steel production, we are here when you need steelwork services.

Wherever you’re based on the Wirral, we can be on hand to make any type of steel fabrication you need. No job is too big or too small for our experts; contact us by calling us at 07500 557 290 or emailing us at now to discuss your fabrication needs.