Difference Between Carbon Steel and Stainless Steel

by AMC

Posted on January 30, 2023 at 12:05 PM

Carbon Steel vs Stainless Steel

Even if two things are made of steel, that doesn't mean they are made of the same kind of steel. There are many kinds of steel, but carbon steel and stainless steel are the most common. Even though they look the same, there are some key differences between the two.

What is Carbon Steel?

What is Carbon Steel?
Carbon steel is a common type of steel made by mixing iron and carbon. It has more carbon, a lower melting point, and lasts longer compared to stainless steel.

Carbon steel has a high amount of carbon, usually up to 2.1% of its total weight. The American Iron and Steel Institute (ASISI) says the following things about carbon steel:

  • There is no minimum amount of chromium, cobalt, nickel, titanium, tungsten, vanadium, or other metals that resist corrosion that must be used.
  • Copper content must be at least 0.40% but no more than that.
  • Manganese can't be more than 1.65% of the total amount.
  • Copper cannot have more than 0.6% of it.
  • The most silicon that can be in a product is 0.6%.
So, what are the benefits of carbon steel?

When there is a lot of carbon in steel, it changes how it works. In particular, it gets stronger and tougher. This is why high-carbon steel is used to make a lot of swords, knives, and other weapons with blades. In feudal Japan, swordsmiths were the first to use tamahagane, which is a type of high-carbon steel, to make weapons like the katana.

Does carbon steel rust?

Yes, carbon steel does rust because it doesn't have the same properties as stainless steel that keep it from rusting. Carbon steel is stronger and lasts longer than stainless steel, but it can rust and corrode if it gets wet. Carbon steel can rust if it gets wet, even if it's just a little bit. This includes moisture vapor in the air. Carbon steel is also harder to bend than stainless steel.

Carbon Steel Composition

Carbon steel is composed of iron and between 0.12% and 2.00% carbon. In the broader definition, alloy steels are also included, which can have up to 10.5% alloy content. Even within a range of less than 2% carbon, there are huge differences in physical properties, especially hardness.

Types of Carbon Steel

The different kinds of carbon steel can be put into the following groups:

Low-carbon steel: This is the most common type. It has less than 0.25 percent carbon. This type of carbon steel is weaker and softer than most, but it is more flexible and easy to weld, so it is used for machining and welding at a low cost.

Medium-carbon steel:
This type usually has between 0.25 and 0.6% carbon and between 0.6 and 1.65% manganese. It can be made better by heating it. But this can only be done on very thin pieces of metal if no alloying elements are added. It is stronger than low-carbon steel, but it is not as easy to bend.

High-carbon steel:
This is the type of carbon steel that is the hardest and toughest. It is the least flexible and wears down the least slowly. The amount of carbon in it ranges from 0.6% to 1.25 %, and the amount of manganese is between 0.3% and 0.9%.

What is Stainless Steel?

What is Stainless Steel?
Stainless steel is an iron alloy that doesn't rust or break down easily. It has at least 11% chromium and may also have carbon, other nonmetals, and metals to get other properties. The chromium in stainless steel makes it resistant to corrosion. The chromium forms a passive film that can protect the material and heal itself when oxygen is present.

Stainless steel, which is also called inox steel (from the French word inoxydable, which means "not oxidized"), lives up to its name by being very resistant to corrosion stains. When iron-based metals like steel are exposed to oxygen, they usually go through a chemical change called "oxidation" that changes how they behave. The iron oxidizes, which turns the hard iron into a metal with a reddish-brown color (iron oxide). At some point, the iron oxide will become so oxidized that it will break up completely.

Stainless steel is made to keep things from rusting. It has at least 10.5% of its weight in chromium. This is important because, unlike iron, chromium doesn't easily rust. Chromium doesn't rust or corrode when it's exposed to oxygen, which makes it an important part of making stainless steel. Stainless steel has a layer of chromium that protects it from corrosion. This layer acts as a barrier between the oxygen in the air and the iron in the metal.

Composition of Stainless Steel
Carbon and iron are mixed together to make steel. Stainless steels have at least 10.5% chromium, less than 1.2% carbon, and other elements that make them stronger. Other elements, like nickel, molybdenum, titanium, niobium, manganese, etc., can be added to stainless steel to improve its resistance to corrosion and its mechanical properties.

Types of Stainless Steel

The following are the types of stainless steel with different properties:

Austenitic: This is the most common type of stainless steel. It has a low yield strength but is resistant to heat and corrosion. It is often used to make home goods, pipes and vessels for industry, buildings, and facades.

Ferritic: This type of stainless steel doesn't usually have nickel in it. But this type promises better resistance to corrosion, heat, and cracks than most other types. This type of stainless steel is often used in washing machines, boilers, and the construction of buildings inside.

Martensitic: This type of stainless steel is usually magnetic and doesn't resist corrosion as well as other types of stainless steel because it doesn't have as much chromium in it. It is also very strong, which is why knives and turbine blades are made from it.

Duplex: This is the combination of austenitic and ferritic steels that is both strong and flexible. It has twice the yield strength of austenitic stainless steel and is used a lot in industries like paper, pulp, shipbuilding, and petrochemicals.

Precipitation: This type of stainless steel is just as resistant to corrosion as austenitic metals, but it can be made even stronger by adding things like aluminum, copper, and niobium.

Stainless Steel vs Carbon Steel

Should I Pick Carbon Steel or Stainless Steel?

Carbon steel and stainless steel are not the same, but that doesn't mean that one is better than the other. It depends on what is going on. Each material has its own pros and cons. The key is to find the right steel for the job.

High Carbon Steel

  • Vulnerable to rust
  • Brittle
  • Wear-resistant
Stainless Steel

  • Resistant to rust
  • Less brittle
  • Less wear-resistant
Contact us if you want to know more about carbon steel or stainless steel, or if you want a quote for a custom project.

1Which is better: carbon steel or stainless steel?

Carbon steel has a lot of carbon, which makes it corrode and rust quickly when it gets wet. Stainless steel looks better and can be used to make decorative items.

2 Is high-carbon steel stronger than stainless steel?

Carbon steel has a matte finish and is harder and has better tensile strength than stainless steel.This material is used to make knives and other tools with blades that need to keep their cutting edge for a long time.

3Is stainless steel cheaper than high-carbon steel?

Costs vary by grade, but stainless steel is usually more expensive than carbon steel. This is mostly because stainless steel is made with chromium, nickel, manganese, and other elements that make it stronger. All of these extra parts add up to a higher price than carbon steels. Carbon steel, on the other hand, is mostly made of iron and carbon, which aren't too expensive. Carbon steel might be the best choice for your next project if you don't have a lot of money to spend.

4 Is carbon steel sharper than stainless?

Carbon steel keeps its edge longer than stainless steel does. Second, and this is important, carbon steel is much easier to sharpen than stainless steel, even though it is harder. This is important because we have found that knives that are used a lot don't stay sharp for long.