Carbon Steel Pipe VS Mild Steel Pipe

When comparing mild steel pipes and carbon steel pipes, it is essential to understand their unique characteristics, applications, and properties. While both belong to the steel family, their carbon content and subsequent properties set them apart, making each type suitable for specific applications.

Generally speaking, steel is called "carbon steel" when the main alloying component used is carbon and no other element requirements are specified; i.e. chromium, cobalt, nickel. Carbon steel can be divided into two major categories: high carbon steel and mild steel. As the name suggests, high carbon steel contains a higher amount of carbon, whereas mild steel contains a lower percentage of carbon. Mild steel is a form of low carbon steel. The main difference between carbon steel and mild steel is that carbon steel has a higher carbon content whereas mild steel has a relatively lower carbon content.

What is a Mild Steel Pipe?

Mild steel is the lowest carbon type of carbon steel, with a relatively low carbon content. Mild steel can also contain other elements such as manganese, silicon, and trace amounts of phosphorus. These added elements protect the integrity of the metallic iron structure by preventing dislocations within the iron crystals. Carbon acts as a hardener, and the percentage of carbon added is directly proportional to the strength of the steel; the strength of steel generally increases with the amount of carbon added.
Mild steel is the most widely used type of steel, used in 85% of steel products in the United States alone. It has become a popular form of iron due to its desirable properties such as ductility, strength, and economical price. Mild steel is often used to produce wire, steel plate, and other construction materials.Mild steel pipes are a type of carbon steel with a low carbon content, typically between 0.05% and 0.25%. This composition makes mild steel:

Malleable and ductile, ideal for bending and shaping.

Affordable, making it a cost-effective option for various projects.

Easy to weld, simplifying construction and manufacturing processes.

Mild steel pipes are commonly used in structural applications, automotive parts, and general-purpose pipelines. However, they lack high strength and corrosion resistance compared to other carbon steels.

What is a Carbon Steel Pipe?

Carbon steel pipes are made from steel alloys with a higher carbon content, generally between 0.3% and 2.0%. These pipes are:

Stronger and harder, suitable for high-stress applications.

Durable, with better wear resistance than mild steel.

Versatile, used for tools, heavy equipment, and industrial piping systems.

Seamless carbon steel pipes, in particular, are valued for their strength, high-pressure resistance, and ability to handle extreme temperatures.

Key Differences Between Mild Steel Pipe and Carbon Steel Pipe

Aspect	Carbon Steel	Mild Steel (Low Carbon Steel)
Definition	Steel with a higher carbon content.	Steel with a relatively low carbon content.
Carbon Content	0.05%–1.70% by weight.	0.05%–0.25% by weight.
Price	More expensive due to its strength and durability.	More affordable and widely used.
Strength	Stronger and harder but more brittle, prone to breaking.	Softer and weaker, easier to shape and weld.
Heat Treatment	Can be successfully heat-treated to increase hardness and strength.	Cannot be effectively heat-treated.
Weldability	Less weldable due to higher carbon content.	Easy to weld and form into different shapes.
Applications	Used for tools, machinery, and structural components requiring strength.	Suitable for lightweight structures, pipelines, and general-purpose uses.

Differences Applications  Between Mild Steel Pipe and Carbon Steel Pipe

Mild Steel Pipe

Structural components such as fences, frames, and supports.
Automotive body parts and exhaust systems.
General-purpose water and gas pipelines.

Carbon Steel Pipe

High-pressure pipelines for oil and gas.
Tools, gears, and heavy machinery components.
Industrial piping systems requiring strength and durability.

Selecting the Right Steel Pipe

When choosing between mild steel and carbon steel pipes, consider factors like machinability, strength, and corrosion resistance. Below are some critical considerations:

Machinability:
Mild steel is easier to machine, making it a better choice for intricate designs. High-carbon steel may require specialized tools for processing.

Weldability:
Mild steel and low-carbon steel weld easily, while high-carbon steel may require preheating and post-weld treatment to avoid cracks.

Strength Requirements:
For high-strength applications, medium or high-carbon steel pipes are better suited. Mild steel pipes are ideal for low-stress uses.

Formability:
Mild steel offers excellent ductility, making it suitable for forming into various shapes. Higher-carbon steels are less ductile but more robust.

Corrosion Protection:
While neither type has inherent rust resistance, galvanizing or painting can improve performance in corrosive environments.

What is Carbon Steel Seamless Pipe?

Seamless steel pipes are made from residual carbon or low-carbon alloy steel. They are generally available in three standard sizes: tapered, half-round, and round. Each size has a different definition, but the bending radius is usually calculated based on the outer diameter. Of course, different categories of seamless steel pipes also have different thicknesses, ranging from 0.5 inches (1.5cm) to 4 inches (10cm).

The special feature of carbon steel seamless steel pipes is that they are manufactured without any welds and seams. This is because the production process of seamless steel pipes uses a precise pressing process, which is a heat treatment technology that compresses the raw material into a complete structure through a rotating die and precise cooling and cutting, and no welding is used in this process.