Cast Iron Types and Applications

Cast iron is one of the traditional materials that continues to hold a stable position in modern industrial production. It is an alloy of iron and carbon, which differs from steel by higher carbon content (more than 2 %). Thanks to its compressive strength, dimensional stability, thermal conductivity, and ability to dampen vibrations, this metal remains indispensable in many technical applications. Whether it's workshop components, machine parts, or structural elements, cast iron offers a combination of proven properties and a wide range of variants. It is a material that can meet a variety of practical requirements.

More about the composition and properties of cast iron


From left: microstructure of gray, ductile, and vermicular cast iron.
Source of the three views: DOI 10.1016/j.ijfatigue.2020.106112. Licensed under CC BY 4.0.

Overview of the most commonly used types of cast iron

However, not all cast iron is the same – there are several types that differ in composition and mechanical properties. Choosing the right grade is key to ensuring the desired functionality of the product.

Gray Cast Iron (GG, EN-GLJ)

Gray cast iron is the most widespread type. It contains flake graphite dispersed throughout the structure, giving it a characteristic gray fracture surface. The flake graphite provides excellent vibration and shock damping, reduces internal stress, improves machinability, and enhances sliding properties. These features make it ideal for parts exposed to dynamic loads, such as:

  • Beds and frames of machine tools, where stability and precision are crucial
  • Engine blocks and heads, benefiting from good thermal conductivity and dimensional stability
  • Brake discs in vehicles, requiring strength and wear resistance
  • Vise bodies, which must absorb clamping shocks
  • Valve and radiator components, where resistance to thermal and mechanical influences is important

It is also used for artistic castings due to its ability to replicate fine mold details.

For workshops and machine part manufacturers, gray cast iron offers an optimal balance of compressive strength, workability, and affordability.

Ductile Cast Iron (GGG, EN-GJS)

Ductile cast iron differs from gray iron by having a higher carbon content (over 3.5%) and alloying elements that cause the graphite to form spherical nodules during solidification. This microstructure significantly increases compressive strength, toughness, and ductility. Thanks to its combination of high strength and impact resistance, ductile iron is used in applications requiring mechanical durability and fatigue resistance, such as:

  • Automotive structural parts like wheel hubs, suspension arms
  • Pipe fittings and pressure vessels needing pressure and impact resistance
  • Agricultural and construction machinery under dynamic loads
  • Pump and compressor components requiring strength and sealing
  • Industrial machine castings exposed to demanding conditions

Ductile iron is ideal where cast iron benefits are needed with properties close to steel.

White Cast Iron (EN-GJN)

White cast iron is produced by rapidly cooling the melt, which causes carbon to form carbides instead of graphite. This gives the fracture surface a lighter color and significantly increases hardness and wear resistance. However, the material becomes more brittle and less ductile. White cast iron is mainly used where high abrasion resistance is needed, such as:

  • Crusher and grinding machine parts, and heavy construction equipment
  • Brake drum surfaces and linings exposed to heat and wear
  • Valve linings and other wear parts in industrial equipment
  • Reinforcements and covers in abrasive environments like quarries or bulk material processing

Despite its brittleness, white cast iron withstands extreme wear, making it essential in heavy industry.

Malleable Cast Iron (EN-GJMB, EN-GJMW)

Malleable cast iron is made by annealing white cast iron, transforming carbides into tempered carbon. This improves compressive strength and toughness, making it more resistant to impact and wear. It is mainly used for:

  • Gears and gearbox housings requiring precision and durability
  • Load-bearing parts in transport and construction machinery like pulleys, levers, and brackets
  • Pump and valve parts exposed to wear in hydraulic or cooling systems
  • Agricultural machine parts like clutches and shafts that endure mechanical shocks and repeated stress

Malleable iron is suitable for demanding technical applications requiring a combination of strength and durability.

Vermicular Cast Iron (EN-GJV)

Vermicular cast iron is named for its graphite shape – curved, worm-like fibers with rounded ends. This structure gives it properties between gray and ductile iron – combining good damping and machinability with higher strength and toughness. It is used for:

  • Engine and brake parts requiring resistance to temperature changes and vibrations
  • Pump and valve components needing strength and precise sealing surfaces
  • Structural parts under dynamic loads in automotive and mechanical engineering

Vermicular iron is a good choice when a balance of strength, durability, machinability, and vibration damping is needed.

Cast iron remains one of the most popular technical materials today. Its various types offer a wide range of properties – from high machinability to extreme wear resistance. Thanks to its versatility, availability, and proven reliability, cast iron maintains a strong position in industrial production, whether for custom workshop manufacturing or demanding serial applications in engineering.

Want to take advantage of cast iron in your production? Contact us for expert advice and high-quality material tailored to your needs.

Send an inquiry

 

31. 07. 2025, 14:29