Alloy Steel and Carbon Steel~7 Best Difference!!

Nov 20, 2023
Why is Difference Between Alloy Steel and Carbon Steel

Alloy Steel and Carbon Steel: We are all familiar with stainless steel as it’s widely used to craft kitchen utensils. When asked what the difference between carbon steel and alloy steel is, many will remain clueless. Both types are metal alloys containing iron; their properties can be modified through the addition of elements. As their names imply, alloy steel contains other elements while carbon steel has higher carbon concentration levels – this article will also address other differences.

Alloy Steel

Alloy Steel
Figure-no-01: Alloy Steel

Alloy steels are steels containing additional elements besides iron and carbon, such as manganese, silicon boron chromium vanadium nickel. Their composition depends on their intended use; often alloy steel is designed to achieve specific physical properties in its final form.

Low alloy and High alloy steels are two primary categories of alloy steels. High alloy steels contain added elements in amounts greater than 8 by weight; low alloy steel is created when this percentage drops below 8. In steel industry applications, low alloy steel is often preferred due to its stronger and more corrosion-resistant qualities, as well as the heat treatment requirements required when adding elements to regular steel.

The carbon content must be reduced in alloy steels in order to make them weldable, typically by at least 0.1% to 0.3% while alloying elements decrease proportionately; these steel alloys are known as low-alloy, high-strength steels. You might be surprised to learn that even stainless steel, with at least 10% chromium by weight, is considered an alloy material!

Carbon steel

Carbon Steel
Figure no 02: Carbon Steel

Carbon Steels have great structural integrity when exposed to extreme temperatures. Carbon steel is an alloy steel composed primarily of carbon. There are no minimum percentage requirements for other alloying elements; thus it falls outside of the stainless steel category but instead falls into the alloy steels category. As its name implies, carbon content increases through heat treatment to make steel stronger and harder; its addition reduces ductility while weldability drops with increasing carbon content; carbon steel accounts for approximately 85% of American steel usage today.

Difference Between Carbon Steel and Alloy Steel

Carbon steel and alloy steel both possess unique qualities that differentiate them from one another, with key differences between them including:

  • Carbon steel’s main constituents are iron and carbon, while alloyed versions include alloying elements like chromium and nickel for additional strengthening effects.
  • Alloy steel outshines carbon steel when it comes to properties. Alloy steel has increased strength, hardness, toughness, and resistance against wear, corrosion, and heat while carbon steel excels at being machineable while remaining affordable and ductile.
  • Due to its more costly composition due to alloying elements, alloy steel’s price tends to exceed that of carbon steel.
  • Carbon steels are widely utilized in construction, automotive, and machinery applications; alloy steels are generally reserved for more demanding applications where strength, durability and wear resistance are essential, such as aerospace, oil & gasoline as well as the tooling industry.
  • Carbon steel is easier than alloy steel to machine due to its lower hardness; however, heat treatment may improve the machinability of alloy.

Carbon steel is ideal for applications where its ductility and affordability make it the superior choice, while alloy steel shines in applications that demand superior strength, durability, and wear resistance. Carbon steel should only be used where its affordability, ductility, strength, and affordability are critical elements; alloy steel on the other hand should only be utilized for more rigorous applications that demand superior strength, durability, and wear resistance.


Carbon Steel Alloy Steel
Iron and carbon Iron, carbon, and alloying elements
Lower than alloy steel Higher than carbon steel
Lower than alloy steel Higher than carbon steel
Easier to machine compared to alloy steel Harder to machine compared to carbon steel
Lower than alloy steel Higher than carbon steel (depending on the alloying elements)
Affordable More expensive than carbon steel
Construction, machinery, and automotive Aerospace, oil and gas, tooling, and other demanding applications
Easier to weld compared to alloy steel Harder to weld compared to carbon steel

Difference Between Alloy Steel and Carbon Steel

The selection of alloy or carbon steel depends on several considerations, including application and budget. When making this choice, bear these in mind:

  • Alloy steel is the optimal material if you require high strength and durability, due to its superior properties when compared with carbon steel.
  • For use in harsh environments, alloy steel offers superior corrosion resistance due to its presence of elements like chromium which increase its anticorrosive qualities.
  • Due to the additional alloying elements present, alloy steel can be more costly than carbon steel; therefore if price is an important consideration, carbon steel might be the better choice.
  • Carbon Steel is easier to work with than alloy steel and may be better suited for applications requiring extensive machining or fabrication processes. If this applies to you, carbon steel could be an ideal material choice.
  • Weldability – Carbon steel is more easily welded than alloy steel, so if your application calls for welding then carbon could be an ideal choice.
  • Taking into account any requirements specific to the application such as temperature resistance and wear resistance is key. Alloy steel may be better suited for applications requiring exceptional properties.

Decisions on alloy or carbon steel depend primarily on your application and desired properties. Before making an ultimate choice, it’s vital that all factors be taken into consideration.

What Are The Similarity Between Carbon Steel and Alloy Steel?

Carbon steel and alloy steel are both kinds of steel with some similarities in composition and characteristics.

Here are a few similarities between carbon steel and alloy steel:

Base Material:

  • Carbon Steel Carbon steel is made up of carbon and iron with traces of various other elements. The carbon content usually ranges between 0.05 percent to 2.0 percent with higher carbon content which results in greater strength and hardness.
  • Alloy Steel Alloy steel is made up of carbon and iron however, it also contains alloying elements that are in various proportions. These alloying elements comprise elements like manganese, chromium, and nickel molybdenum, among other elements. They are alloying elements that confer specific characteristics to the steel.

Strength and Hardness:

  • Carbon steel as well as alloy steel display varying levels of hardness and strength dependent on their composition as well as the heat treatment. Carbon content as well as alloying components are the key factors that affect the steel’s mechanical characteristics.


  • Carbon steel as well as certain alloy steels is machinable, making them suitable for a variety of manufacturing processes, such as drilling, machining, and shaping.


  • Both kinds of steel are able to be welded, but the speed of welding is contingent on the particular nature and the treatment that is applied to the steel. Certain alloying elements can impact the weldability of the steel, and appropriate welding techniques could be required.

Availability and Cost:

  • Both alloy and carbon steel are widely available materials. Carbon steel, which is less complex in its composition, is typically cheaper than alloy steel which can contain more expensive alloying elements.


  • Both kinds of steel be found in a variety of types and grades with distinct characteristics that are appropriate for various applications. The variety of grades available allows for customizing depending on the required mechanical properties, resistance to corrosion, and other specifications.

Heat Treatment:

  • Both carbon and alloy steel are able to undergo heat treatment processes like quenching, annealing and tempering to alter their properties. Heat treatment can improve strength, hardness, and other properties.

It is important to recognize that although carbon steel and alloy steel have some commonalities, they have distinct differences due to the inclusion of alloying components within alloy steel. Alloy steel is able to be tailored to specific requirements by adjusting the proportions of alloying elements resulting in a variety of properties such as mechanical, resistance to corrosion and other attributes.


Carbon and alloy steels have multiple applications in many fields. Carbon steel is composed primarily of iron and carbon and offers cost-effective, ductile, and easily machinable performance; alloy steel contains additional alloying elements, such as nickel, chromium, or molybdenum that add strength, durability, corrosion resistance, and heat tolerance to its strength and performance.

Before choosing between carbon and alloy steel materials for any given task or application, it’s essential to carefully consider both their costs and properties required for success. Alloy steel costs more, yet is often necessary due to high strength, durability, corrosion resistance, or temperature/wear resistance requirements. Carbon steel may offer lower costs while providing affordability, ductility, and ease of machining capabilities; in the end, a careful evaluation will help select the ideal material.