Steel is the backbone of various modern industries, helping shape the world around us. Among the many types available, two of the most widely used are carbon and stainless steel. Some choose stainless steel because of its shiny appeal. However, some prefer carbon steel because of its incredible hardness. This contrast often sparks the debate: carbon steel vs stainless steel.
Remember, both steels possess unique features and are specific for different applications. So, choosing the right one for your project is the key to flawless outcomes. Making the wrong choice can lead to costly repairs and safety issues. So, how would you decide which one suits you better? Fret not! This article will make things clear for you by differentiating both. So, let’s get started!
Overview of Carbon Steel and Stainless Steel
Before we dive into the differences, let’s first understand carbon steel and stainless steel separately.
Carbon steel is a special type of steel that primarily contains carbon and iron. It also contains small amounts of other metals, such as chromium and nickel. However, the major content is carbon, typically about 0.05% to 2.0%. This carbon content can vary from type to type.
If we look at its appearance, carbon steel has a dull, matte, and bluish-grey finish. Moreover, when exposed to air, it develops a patina. It is a yellow layer that further makes its appearance dull. However, you can improve its appearance by applying coatings and polishing.
Types of Carbon Steel
Based on carbon content, carbon steel is divided into three main types;
- Low-carbon steel (Mild Steel) has about 0.30% carbon content. Due to its low carbon content, it is soft and flexible. Thus, it is mainly used in wires and pipes.
- Medium Carbon Steel contains 0.30% to 0.60% carbon. This slightly higher content makes it hard to some extent. Still, it is flexible and used to make structural parts.
- High Carbon Steel: This type contains a carbon percentage of about 0.60% to 2.0%. Higher carbon content means more hardness. Thus, this type is the hardest and is used in cutting tools.
Stainless steel is an alloy that primarily contains chromium as the main content. The chromium percent amount is about 10.5%, which gives it unique properties. However, along with chromium, it also includes carbon, iron, molybdenum, and nickel. These different metals further enhance their features.
This difference in composition affects the appearance of stainless steel. For example, it has a shiny, smooth, and polished look. This reflective appearance makes it a top choice for architectural projects. Moreover, you can further enhance its look with a brushed, matte, or glossy mirror-like texture.
Types of Stainless Steel
Here are the three main types of stainless steel, depending on composition
- Austenitic Stainless Steel: This type contains higher chromium and nickel content. It has non-magnetic properties and offers easy weldability.
- Ferritic Stainless Steel: It contains higher chromium but low nickel content. This makes it magnetic and hard. Thus, it is used in automotive parts.
- Martensitic Stainless Steel: This type has chromium with a higher carbon content. Thus, it is robust but less corrosion-resistant. It is mainly used in knives and cutting tools.
Carbon Steel vs Stainless Steel: Key Differences!
Have you understood the basic composition and appearance differences? If so, it is far easier to understand further distinctions. So, let’s explore how these two materials stack up against each other.
1- Strength and Durability
This is one of the prominent differences between stainless steel and carbon steel. As you know, carbon steel has a higher carbon content, which makes it harder and stronger. However, there is a trade-off: its higher hardness makes it brittle. This means carbon steel has less tensile strength, and if not handled carefully, it can break.
On the flip side, stainless steel offers the best combination of strength and durability. For example, it has a higher tensile strength of 87,000 psi. It means when pulled or stretched, it does not break easily. Moreover, a changing environment like a cold does not make it brittle. So it can last for a long time and ensure durability.
2- Corrosion Resistance
Corrosion resistance is another factor that sets both steels apart. In this term, stainless is the clear winner. WHY? As you know, it has a higher chromium content. When exposed to air or moisture, an oxide layer develops. This layer acts as a protective shield and saves the surface from further resistance. Moreover, this layer can self-heal.
This means it can reform quickly if it vanishes in harsh conditions. On the other hand, carbon steel does not have enough chromium to resist corrosion. When exposed to oxygen, it rusts and corrodes. As a result, the carbon steel surface becomes weak and cannot handle moisture. However, you can improve this property by galvanizing, painting, and coating.
3- Weight and Handling
This is one of the significant differences between stainless steel and carbon steel. If we discuss carbon steel, it is highly lightweight. WHY? The reason lies in its lower density, which is about 7.85 g/cm³. This low density is due to loosely packed atoms. That’s why carbon steel is also easy to handle. You can easily carry, install, and shift it anywhere.
On the reverse side, stainless steel is much heavier due to its higher density. Due to tightly packed atoms, it has a density of about ~8.00 – 8.10 g/cm³. Stainless steel has more alloying elements, which also contribute to increasing its weight. Thus, its weight also makes it challenging to handle. You will need special tools and attention to handle it.
4- Weldability and Workability
These two terms refer to how easy it is to weld and shape a material. This is another difference that differentiates both types of steel. For example, carbon steel is easier to work with and weld, especially when it is low and medium-grade. Its lower density responds well during cutting and milling. Moreover, due to the low alloying element, it does not wrap or crack during welding.
On the other hand, stainless steel is much heavier, which makes it challenging to work with. Special tools and techniques are required to cut and perform other milling operations. Moreover, its nickel content behaves differently in heat, which is also a problem during welding. Thus, welding stainless steel has a higher chance of discoloration and warping.
5- Magnetic Properties
Magnetic properties refer to how a material behaves in a magnetic field. This property greatly matters in several applications, such as transformers and magnetic sensors. So, how do both types of steel differ in this regard? Carbon steel is highly magnetic due to its higher iron content. As you know, iron has unpaired electrons that attract the magnet quickly.
So, each type of carbon steel, no matter if it is a lower poor medium, attracts magnetic. Conversely, stainless steel’s magnetic properties depend on its type. For example, austenitic stainless steel is completely non-magnetic. However, ferritic steel can significantly attract magnetism. The last type, martensitic, has magnetic properties. This difference is because of the different iron content.
6- Heat Resistance
It is one of the significant factors that help us understand the key differences. Heat resistance shows how efficiently a material can handle high temperatures. If we look at carbon steel, it has moderate to low heat resistance. For example, when exposed to heat for an extended period, it oxidizes and weakens. This is due to its lower melting point.
In contrast, stainless steel has a higher amount of chromium. This makes it more heat resistant due to the formation of an oxide layer. Even if you explode a stainless steel sheet to heat for a long time, it develops an oxide layer but does not weaken. Moreover, its higher melting point also makes it stronger and prevents deformation.
7- Maintenance
Both stainless steel and carbon steel offer different levels of maintenance. For instance, carbon steel requires more care and maintenance. WHY? As I said above, it has a dull appearance and less corrosion resistance. Thus, you must apply coatings and polishing to use it for outdoor applications. Moreover, regular cleaning is also crucial to keeping it in the same condition.
However, stainless steel is convenient for maintenance. It has a naturally polished and shiny appearance, so you don’t have to apply coatings and polish. Moreover, due to its higher chromium content, it is naturally corrosion-resistant. It develops an oxide layer, which protects it from rusting. Thus, it remains in the same condition even in harsh conditions.
8- Applications
Due to different compositions, the usability of both steels varies across various industries. Let’s first look at the typical applications of carbon steel.
- Because of their strength and affordability, carbon steel pipes are used in building beams and columns.
- Due to its toughness, it is commonly found in vehicle parts, such as chassis.
- Carbon steel is highly used in making tools such as hammers and knives.
- You can also find it in machinery parts such as gears and shafts.
As you know, stainless steel is highly durable and corrosion-resistant. Thus, its applications include:
- It is used in the food and beverage industry due to its corrosion resistance and ease of cleaning.
- Stainless steel’s non-porous surface makes it hygienic. Thus, it is used to make surgical tools, implants, and medical devices.
- As I said above, it maintains its shine for several years. This is considered for exterior finishes, handrails, and roofing.
- Due to higher heat resistance, stainless steel pipes are used in aerospace parts such as engines.
9- Eco-Friendliness & Sustainability
Both stainless steel and carbon steel differentially impact our environment. For example, carbon steel is recyclable but still not a good eco-friendly material. WHY? First, it is less durable and has less lifespan, increasing the overall environmental footprint. Moreover, carbon steel is more prone to corrosion and needs to be replaced often. This increases the need for new production materials.
On the flip side, stainless steel has no such problem. It is more eco-friendly than carbon steel. First, it is highly durable and lasts for a long time. This reduces frequent replacements, which directly reduces production material waste. Moreover, it has a shiny surface naturally; thus, it does not require coatings. These coatings use harmful chemicals that contribute to pollution.
10- Cost and Affordability
Cost matters greatly when choosing between stainless steel and carbon steel. Both of these materials have different price ranges. For example, carbon steel is an affordable option. WHY? First, it has fewer alloying elements that come at lower prices. Moreover, because it is lightweight, its fabrication is also easy. It means you can create carbon steel coils with basic tools.
However, remember that carbon steel wins only at the initial cost. Its long-term expenses can add to the overall cost. On the flip side, stainless steel has a higher initial cost. The reason lies in its costly alloying elements. Moreover, it is a heavier material, so its fabrication requires expensive tools and processes. But, its long-term durability and low maintenance compensate for its price and make it cost-effective in the long run.
Can You Tell the Difference by Looking?
“Sometimes yes, but not always.” As I said above, both of these steels have different appearances. So, if you find a shiny and smooth steel, it is probably stainless steel. On the other hand, dull and matte appearances are specified in carbon steel. But you can get confused, as carbon steel also looks shiny due to coatings and finishes.
Another method for visually identifying is the magnet test. As you know, carbon steel is a magnetic material that can attract a magnet. However, stainless steel cannot attract magnetism. So bring the magnet near a steel and check whether it is carbon or stainless steel. However, keep in mind that this method is not 100% reliable. Some grades of stainless steel can also attract magnets.
Carbon Steel vs Stainless Steel: Which One Should You Choose?
Both of these materials offer unique properties. So, it’s tricky to find the most reliable option. However, some factors can help you make an easier decision. Let’s see how to choose between stainless steel and carbon steel.
- First, consider the corrosion-resistant factor of both materials. Stainless steel is more rust-resistant, so I prefer it for outdoor and humid places. However, for indoor uses, go with carbon steel.
- Evaluate the strength and toughness of both materials. For example, choose carbon steel if you need something powerful, such as tools and frames. However, if stretchiness is your preference, go for stainless steel.
- Appearance and maintenance are other factors you must consider. For instance, stainless steel is better if your project requires a shiny, smooth look. Moreover, it also requires less maintenance. However, if appearance does not matter but hardness matters, go with carbon steel.
- Lastly, keep your budget in mind while choosing between these steels. If you have a tight budget, carbon steel proves a cost-effective option. However, if you aren’t concerned about budget but prefer more features, you should pick stainless steel.
Conclusion
Carbon steel and stainless steel are two incredible materials, each offering its own strengths. The key is to choose the right one for your needs. This is only possible when you know the fundamental difference between them. Thus, I have explored the primary difference that helps you out in this article. For example, carbon steel is more reliable if you prefer hardness over strength.
However, if corrosion resistance is your primary concern, stainless steel provides this feature. Lastly, remember there is no one-size-fits-all answer. Every application has requirements, so choosing the right one makes all the difference. Thus, consider the pros and cons of each material and make the best decision about your project.