What Is Gray Cast Iron?
Gray cast iron is an alloy of iron, carbon and silicon characterized by graphite in the form of flakes. This structure provides good machinability, strong vibration-damping properties and effective heat dissipation.
Produced in Quebec, our gray cast iron is suitable for a variety of industrial applications, including mechanical components, housings, complex-shaped castings and municipal equipment.
What Are the Advantages of Gray Cast Iron?
Gray cast iron is particularly valued for its machinability and properties suited to a wide range of mechanical and industrial applications.
- Good abrasion resistance depending on the class
- Good heat dissipation
- Excellent machinability
- Good vibration-damping capacity
- Cost-effective solution for many industrial applications
Gray Cast Iron Composition and Mechanical Properties
Gray cast iron contains graphite in the form of flakes, unlike ductile iron, in which the graphite forms as spheres. Gray cast iron is particularly valued for its machinability, compressive strength, abrasion resistance and vibration-damping properties.
ASTM A48 Gray Cast Iron Classes and Mechanical Properties
The ASTM A48 classes presented below are distinguished primarily by their minimum tensile strength.
| ASTM A48 Class | Tensile Strength (psi) |
| 20 | 20 000 |
| 25 | 25 000 |
| 30 | 30 000 |
| 35 | 35 000 |
| 40 | 40 000 |
| 50 | 50 000 |
ASTM A48 Gray Cast Iron Class Equivalents
| ASTM A48 | EN-GJL | GG |
| Cl20 | EN-GJL-150 | GG-15 |
| Cl25 | EN-GJL-200 | GG-20 |
| Cl30 | EN-GJL-250 | GG-25 |
| Cl35 | EN-GJL-300 | GG-30 |
| Cl40 | EN-GJL-350 | GG-35 |
| Cl50 | EN-GJL-400 | GG-40 |
Gray Cast Iron Expertise in Quebec
Produced and machined in Quebec, our gray cast iron combines local foundry expertise with recognized standards to meet the requirements of a variety of industrial applications.
- Certified in-house quality control
- Technical guidance for selecting the appropriate class for your parts
- Delivery and technical support for the Canadian market
Discuss your gray cast iron project
Frequently Asked Questions About Gray Cast Iron
What Is the Difference Between Gray Cast Iron and Ductile Iron?
The main difference is the shape of the graphite. Gray cast iron contains graphite in the form of flakes and is particularly valued for its machinability and vibration-damping properties. Ductile iron contains graphite in the form of spheres, providing greater ductility and impact resistance.
What Are the Main Applications of Gray Cast Iron?
Gray cast iron can be used for mechanical components, housings, complex-shaped industrial castings, pump components and certain types of municipal equipment.
Which ASTM A48 Gray Cast Iron Classes Are Presented?
The ASTM A48 classes presented are 20, 25, 30, 35, 40 and 50. They are distinguished primarily by their minimum tensile strength, ranging from 20,000 to 50,000 psi.
