Pipes are an integral component, making our lives possible. From transportation to construction, pipes have multiple uses. Different types of pipes are available, and they differ from each other in many ways. Among those types, carbon steel vs cast iron pipes has always been a topic of debate.
Both of these pipes have pros and cons. Carbon steel is lightweight and inexpensive, while cast iron pipes are very durable. Such differences ignite their comparisons among the people. But worry not! This guide will provide you with their fundamental distinction. So, let’s get started!
Overview of Carbon Steel & Cast Iron Pipe
Carbon steel is a mixture or alloy of carbon and iron. The quantity of carbon is typically between 0.04% and 2.5%. On the other hand, cast iron pipes are made by heating and molding the iron. They contain higher carbon quantities, typically around 2-4%. They also have some alloy elements such as silicon, manganese, etc.
Both of these pipes have unique properties. Carbon steel is strong and less brittle, while cast iron pipes are very brittle. Due to its brittle nature, cast iron pipes cannot undergo a welding process and can break under high temperatures. Remember that carbon steel is versatile and available in different types.
The types of carbon steel vary in terms of carbon content. Due to their excellent strength, these pipes are standard in construction work. Many people love cast iron because of its silent nature. It does not make any noise when fluid flows through it at high temperatures, making it common in fluid transportation.
Differences between Carbon Steel and Cast Iron Pipe
Both of these pipes offer unique value propositions. However, understanding their significant differences is crucial for decision-making. Let’s explore their distinctions.
1- Composition
One of the most significant differences between these two pipes is their composition. They both contain carbon and iron. However, they have different carbon content, which makes them unique. Carbon steel contains 0.04% and 2.5%, which is not high. Keep in mind that higher carbon content makes pipes harder and brittle.
Cast iron pipes have a higher carbon content, ranging between 2% and 4%. Along with carbon and iron, cast iron pipes contain some other alloy elements. Those include silicon and manganese, the proportion of which is deficient. Due to the high carbon content, these pipes are very brittle, which makes them sensitive to welding.
2- Strength and Ductility
Both carbon steel and cast iron pipes are strong. However, carbon steel pipes are well known for their excellent tensile strength. They can easily bear stress. Due to their low carbon content, they are less brittle and more ductile.
On the contrary, cast iron pipes are rigid and brittle. This is because they have a higher carbon ratio. This brittleness can be a big issue for the customers. When they undergo stress, they break instead of being malleable or ductile. Their tensile strength is also low due to brittleness.
3- Corrosion Resistance
Unfortunately, neither of these pipes is rust-proof. When used in harsh conditions, they deteriorate due to corrosion attacks. If we compare these two head-to-head, iron-cast pipes have slightly better corrosion resistance. The reason is that they contain higher carbon content, which supports oxide formation.
This layer of oxide protects the pipe from rust to some extent. However, over time, this layer also starts to deteriorate. As a result, rust will affect the pipes, and you’re more likely to see leakage issues due to rusting. Moreover, manufacturers apply a thin layer of coating to enhance rust protection. This, too, is a short-term solution.
4- Durability & Safety
Cast iron pipes are very durable. Their higher carbon content makes them hard and strong. Despite their brittleness, they remain in good shape for many years. As you know, they are used in fluid transportation, so they don’t feel stress from the side.
These pipes remain in good shape for at least 90 to 100 years. Carbon steel pipes, on the other hand, have slightly compromised durability and last for 50 to 60 years. However, these pipes are very safe for the environment.
They are made from recycled materials. After their damage, they can be recycled, so they don’t leave waste in the environment. Moreover, they don’t give off harmful chemicals during use, which is another safety benefit. Cast iron pipes emit toxic chemicals with water when used for a long time.
5- Weight and Ease of Installation
Carbon steel pipes are very lightweight, so carrying them from one place to another is easy. Iron-cast pipes, on the other hand, are very heavy. Due to their higher weight, their installation is also very tedious. You’ll have to hire a team to install these pipes. On the contrary, carbon steel pipes are easy to install because they are lightweight.
6- Uses & Applications
Cast iron pipes have diverse applications and are usable across different industries and sectors. However, they are primarily used in liquid transportation, such as oil and gases. Moreover, plumbers use them in water supply lines. The reason is that they don’t make noise when high-pressure fluid passes through them.
On the other hand, carbon steel pipes are ductile and have high tensile strength. Due to these factors, they are used in construction works. They help make building frameworks, supports, and scaffolding. The usability of both these pipes is excellent, and they serve different industries.
7- Weldability & Machinability
I mentioned at the start that cast iron has a high content and is brittle. Due to this brittleness, it does not offer excellent machinability. If you apply stress to these pipes, they will start to crack or break. Similarly, they don’t support welding. Upon heating, these pipes break due to their brittle nature.
The carbon steel has a lower carbon content and is ductile. So it can undergo machinability with ease. Not only this, welding these carbon steel pipes is also viable. You don’t have to worry about its breaking or deterioration while welding. So, carbon steel is a better option for welding and machining.
8- Cost & Affordability
Cast iron pipes are costly and fall into the premium category because they are durable. On the flip side, carbon steel pipes are compromised in terms of durability. So, the prices of these pipes are lower than those of cast iron pipes. If you’re a budget-conscious person, carbon steel is a suitable option.
Verdict About Carbon Steel vs Cast Iron Pipe
As I said earlier, both of these pipes are excellent. Their unique value proposition leads us to their comparison. However, carbon steel pipes are a suitable option as these are budget-friendly. They don’t break the bank and offer optimal performance.
You can weld them with ease. Their ductility, high tensile strength, and low weight make these pipes stand out. As they are robust, using them in construction won’t give you any issues. But cast iron pipes are an option if you want something ideally durable. They are premium and long-lasting.
However, the prices of these iron-cast pipes are very high. In the end, their selection comes down to usability and pricing. Iron cast is the best solution if you have a decent budget and want pipes for fluid transportation. The rest is your choice: choosing any of them won’t make you regret it.
Conclusion
Carbon steel and cast iron pipes are indeed dominating the industry. Their uses and applications are widespread. Carbon steel, being ductile, offers many unique features. Cast iron is expensive, but it is undoubtedly worth the price. Their final selection comes down to personal preferences. In this guide, I have covered each of their differentiating aspects.