Carbon Steel


Carbon steel is a metal alloy made of iron and carbon. It is also known as plain steel. Carbon steel can be divided into three subcategories:

  • Low-carbon steel
  • Medium-carbon steel
  • High-carbon steel.

Iron-based mixtures are considered alloy steel when the manganese content is greater than 1.65 percent, silicon quantity is more than 0.5 percent, copper content is above 0.6 percent, or the alloy contains other minimum quantities of elements such as nickel, chromium, molybdenum, tungsten, or vanadium.

An enormous variety of carbon steels with a variety of distinct properties can be created by substituting these elements in the recipe to increase hardness, strength, or chemical resistance.


Low-carbon steel, with a carbon content of less than 0.25 wt. percent, is the most common type of carbon steel.


  • Cannot be hardened by heat treatment (to form martensite)
  • Hardening requires cold work
  • A relatively soft steel
  • Low strength
  • High ductility
  • Excellent for machining and welding
  • Low cost

High-strength, low-alloy carbon steels (HSLA) contain elements such as copper, nickel, vanadium, and molybdenum in up to 10 wt. percent of the steel content.


  • Heat treatment results in higher strength
  • Higher ductility
  • Easily formable and machinable
  • More resistant to corrosion than plain low-carbon steels


Medium-carbon steel is defined as a steel that contains a carbon content of 0.25 – 0.60 wt. percent and a manganese content of 0.60 – 1.65 wt. percent. Medium-carbon steel’s mechanical properties are improved with heat treatment that involves austenitizing, quenching, and tempering. This also gives medium-carbon steel a martensitic microstructure.

Heat treatment can only be performed on very thin sections of the steel. Adding alloying elements to medium-carbon steel, such as chromium, nickel, and molybdenum improve medium-carbon steel’s ability to be heat treated and hardened.


  • High strength
  • Reduced ductility and toughness
  • Tremendous load carrying ability
  • Wear resistance


High-carbon steel requires a carbon content of 0.60 – 1.25 wt. percent with a manganese content of 0.30 – 0.90 wt. percent. Tool steels and die steels are two types of high-carbon steels. They contain additional alloying elements including chromium, vanadium, molybdenum, and tungsten. These elements form carbide compounds such as tungsten carbide (WC) and result in a very hard and wear-resistant steel.


  • Highest hardness and toughness of all types of carbon steels
  • Wear-resistant (from hardening and tempering)
  • Moderate ductility (tolerance to deformation without breaking)

Whether you require low-carbon, medium-carbon or high-carbon steel, Denver Rubber Company is your number one source for carbon steel products. We will work with you to get you the products you need. Contact us today.

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