As someone in the magnetic materials industry, I frequently encounter the use of various grades of carbon steel in magnetic components. Thus, I’ve written this blog to provide a concise introduction. In the realm of industry and manufacturing, steel stands as an indispensable material, with carbon content being a pivotal defining factor in different steel types. This article delves into three primary steel categories: low-carbon steel, medium-carbon steel, and high-carbon steel, outlining their distinctions and typical designations.

Low Carbon Steel

With carbon content ranging from 0.05% to 0.30%, low-carbon steel boasts the following traits:

  • Excellent weldability and forgeability.
  • Easy to machine and shape, displaying high cold formability.
  • Relatively soft, unsuitable for high-strength applications.

Common low-carbon steel designations include:

  • Q195
  • A36 (American standard)
  • S235JR (European standard)
  • SS400 (Japanese standard)
  • 1010
  • 1020

Low-carbon steel finds widespread use in manufacturing automotive parts, structural components, and lightweight machinery, where high strength is not paramount.

Medium Carbon Steel

With carbon content ranging from 0.30% to 0.60%, medium carbon steel exhibits the following features:

  • Weldability and forgeability intermediate between low and high-carbon steel.
  • Possesses moderate strength and hardness, fitting applications requiring strength and wear resistance.

Common medium carbon steel designations include:

  • 1045
  • 4140 (alloy medium carbon steel)
  • 45# (China’s GB/T 699 standard for medium carbon steel)
  • C45 (European standard)
  • S45C (Japanese standard)

Medium carbon steel finds application in manufacturing bearings, gears, bolts, and other components needing moderate strength and wear resistance.

High Carbon Steel

With carbon content typically exceeding 0.60%, high-carbon steel is characterized by:

  • High strength and hardness, yet reduced forgeability and weldability.
  • Susceptibility to brittleness, necessitating precautions against excessive cooling and stress concentration.

Common high-carbon steel designations include:

  • 1095
  • 5160 (spring steel, alloy high carbon steel)
  • 1080
  • 60Si2Mn (spring steel, alloy high carbon steel)
  • SK5 (Japanese standard, commonly used for tool manufacturing)

High-carbon steel is suitable for crafting tools, springs, high-strength components, and other applications demanding elevated hardness and wear resistance.

By understanding diverse carbon steel types, we empower ourselves to select materials best-suited for specific applications, optimizing performance and benefits. Whether it’s low-carbon steel, medium-carbon steel, or high-carbon steel, each excels within its designated realm.