Carbon Steel

• Low Carbon Steel (Mild Steel):

  • Carbon Content: Up to 0.3%
  • Characteristics: This type of steel is known for its high ductility and good weldability. It is relatively soft compared to other types of carbon steel, making it easy to machine and form. Its lower carbon content results in lower tensile and yield strengths.
  • Applications: Commonly used in construction (e.g., beams, columns), automotive parts, and machinery where high strength is not critical but good formability and weldability are desired.

• Medium Carbon Steel:

  • Carbon Content: 0.3% to 0.6%
  • Characteristics: Offers a balance between strength and ductility. It is stronger and harder than low carbon steel but less ductile. Medium carbon steel often requires heat treatment to achieve desired mechanical properties.
  • Applications: Ideal for applications requiring moderate strength and wear resistance, such as axles, gears, and shafts.

• High Carbon Steel:

  • Carbon Content: 0.6% to 1.0%
  • Characteristics: Known for its high strength and hardness due to the elevated carbon content. However, it is less ductile and more brittle, which can make it more challenging to weld and machine. High carbon steel has excellent wear resistance and edge retention.
  • Applications: Used in tools (e.g., cutting tools, knives), springs, and high-strength wire, where strength and wear resistance are crucial.

Property/Specification	Low Carbon Steel	Medium Carbon Steel	High Carbon Steel
Carbon Content	Up to 0.3%	0.3% to 0.6%	0.6% to 1.0%
Tensile Strength	Approx. 370 MPa	370 MPa to 700 MPa	700 MPa to 1,200 MPa
Yield Strength	Lower than tensile strength	Varies, generally 50-60% of tensile strength	Higher than tensile strength
Hardness	Lower, typically around 120-180 HB	Moderate, typically around 180-300 HB	Higher, often above 300 HB
Ductility	High	Medium	Lower
Machinability	Good	Moderate	Poor
Weldability	Good	Moderate	Poor
Applications	Construction, automotive, general structural applications	Axles, gears, shafts, structural components	Cutting tools, springs, high-strength wire
Heat Treatment	Annealing, normalizing	Quenching and tempering, normalizing	Quenching and tempering
Standard Specifications	ASTM A36, ASTM A569	ASTM AISI 1045, ASTM AISI 1030	ASTM AISI 1095, ASTM AISI 1080
Chemical Composition	Minimal Mn, Si; S and P in trace amounts	Higher Mn, Si; S and P in trace amounts	Higher Mn, sometimes other alloying elements