The Differences Between Ductile Iron and Gray Iron Castings

Gray iron and ductile iron are differentiated by the type and structure of the carbon present in them.  The question, of course, is which one is proper for your project?  Before we look at possible answers, let's see some of the key differences between the two cast irons.  

Key Differences

1. Ductility 
   

2. Tensile and Yield Strength 
   

3. Impact 
   

4. Thermal Conductivity  

5. Vibration Dampening 

Gray iron can be cast very easily and has good machineability.  It is typically used in the following non-critical applications where strength is not the main required property:

• Manhole covers

• Counter weights

• Machinery bases for vibration dampening

Ductile Iron, because of the increased strength and ductility is used in more engineered applications:

• Cable drums

• Frames

• Gear boxes

• Pumps