The Difference between Ductile Iron and Gray Iron
Ductile and gray iron are the most common metals used in continuous casting due to their low material cost, high machinability, and high performance. Both metals are used for various applications, including construction equipment, pipe fittings, oil field machinery, and transportation services.
Due to differences in carbon levels, each metal has its advantage and is used for different applications based on its strengths.
| Gray Iron | Ductile Iron | |
|---|---|---|
| Tensile Strength | – | + |
| Thermal Conductivity | – | + |
| Ductility | – | + |
| Vibration Damping | + | – |
| Yield Strength | – | + |
| Machinability | + | + |
Contact continuous cast iron suppliers for raw gray and ductile iron stock. |
||
- Gray iron’s tensile strength ranges from 20,000 psi – 60,000 psi, whereas ductile iron ranges from 65,000 psi – 80,000 psi and can be heat treated to 100,000 psi
- Ductile iron has lower thermal conductivity, so that it can insulate better than gray iron
- Ductile iron is more tailored for engineering applications
- Graphite in ductile iron is nodular and flaked in gray iron—meaning ductile iron is stronger and contains higher ductility
- Gray iron dampens vibration better than ductile iron
More details about Versa-Bar gray and ductile iron
Gray Iron
Lawton Standard has the best replacement for steel in the form of V-2 Class 40 Versa-Bar continuous cast gray iron. During solidification, rod-like graphite flakes precipitate into the composition, outlining the difference between gray and ductile iron. Producers utilize grey continuous cast iron for its high density and strength, but its popularity comes from its low cost. Continuous cast gray iron combines affordable prices with quality lightweight metal to create a material ideal for applications such as vibration damping and use in manufacturing equipment frames. Gray iron is also applied in:
- Construction equipment
- Valves and fittings
- Compressors and pumps
- Diesel engine parts
- Transportation system components
Gray iron is often mistakenly described as cheap and dirty metal. Still, its high cutting speeds, superior damping ability, durability, and unique metallurgical makeup make it popular. Part of the gray iron’s success comes from its ability to be easily machined and used where strength is not a critical requirement, such as maintenance hole covers and counterweights. Gray iron is considerably stronger than steel and costs less. You’ll save money in the short AND long run. Consider gray iron for immediate steel replacement. Ductile iron is the next step up.
Ductile iron
Ductile continuous cast iron has made its name in the machining industry from its high tensile strength and flexibility. Its flexibility makes it great for being shaped into wires and other applications requiring elasticity. Instead of rod-like flakes, the ductile iron bar is composed of graphite nodules, which makes it flexible during solidification. This type of iron is often used in areas that require the ability to elongate under tension. It is most often used in:
- Couplings
- Machine frames
- Hydraulic valves
- Pumps
- Gearboxes
The many advantageous features of continuous cast ductile iron make it the perfect alternative to steel. Lawton Standard offers two high-quality ductile iron grades, V-3 and V-4. The distinctive metallurgic composition of V-3 65-45-12 iron makes it the easiest to machine out of the three grades of continuously cast metal. V-4 80-55-06 ductile iron is stronger than V-3 and popular for automobile parts and hydraulic cylinders. Ductile iron is not only more versatile than steel but costs significantly less. Buying Versa-Bar continuous cast ductile iron from Lawton Standard means savings on every project.
Lawton Standard delivers raw stock and custom iron components
Ductile iron stock is available for sale as a raw material for you to process and finish independently. Alternatively, we can finish and machine it into custom continuous cast iron components based on your requirements at our state-of-the-art CNC facility in Waukesha. It’s up to you. We provide you with high-quality ductile iron in whatever form you desire.
Contact us for continuous cast iron supply, custom metal components, and raw gray and ductile iron stock.