Grey (Lamellar) Cast Iron Castings
Grey (Lamellar) Cast Iron
The best material for vibration damping and economical machining
Specialist foundry — Industrial Zone, Abu Zaabal, Qalyubia, Egypt
The European standard for lamellar graphite cast iron. The EN-GJL designation corresponds to the older GG designation.
In grey iron the graphite forms as flakes, and this is what gives it its main advantage: an exceptional ability to absorb vibration, which is why it is used for machine bases and housings. Those same flakes are also the reason for its weakness under impact, because they act as starting points for cracks. As a specialised grey iron foundry, we cast its standard grades for machine bases, housings and pulleys.
Grey iron grades to EN 1561
| Grade | Designation | Tensile N/mm² | Yield N/mm² | Elongation % | Hardness HB | Structure |
|---|---|---|---|---|---|---|
GG20 Economical for general parts | EN-GJL-200 | — | — | — | — | Pearlitic / ferritic |
GG25 Most widely used | EN-GJL-250 | — | — | — | — | Pearlitic |
GG30 For more heavily loaded parts | EN-GJL-300 | — | — | — | — | Pearlitic |
Grey iron has no specified yield strength in the standard, because it fractures without appreciable plastic yielding (brittle fracture). Design with it therefore relies on tensile strength with a higher safety factor. Values are measured on a standard specimen; the actual value in the casting is affected by section thickness.
Chemical composition
As with ductile iron, composition is indicative here. The binding criterion is the mechanical properties, and section thickness affects the value obtained in the actual part.
Advantages
- •The best vibration damping of any casting material
- •Excellent machinability at low cost
- •Good dimensional stability
- •Self-lubricating at friction surfaces
Limitations and considerations
- •Brittle — fractures without warning under impact
- •Low tensile strength compared with ductile iron and steel
- •Not suitable for shock or high tensile loads
Common applications
Sectors
International equivalents
Data sources and scope
The values above are taken from standard EN 1561 and represent the reference standard limits. The actual properties of any delivery are established by the foundry's analysis and test certificate for that specific heat, and are affected by section thickness, casting conditions and heat treatment. Final material approval for any application is subject to a joint technical review with our engineering team.
Need a casting in Grey (Lamellar) Cast Iron?
Send your drawing or sample — our technical team will review it and recommend the most suitable grade.
