Ductile Iron Grades
& Specifications
A comprehensive technical reference guide to spheroidal graphite (SG) iron grades, mechanical properties, and international standards.
Equivalent Standards
- European: EN 1563 (GJS)
- American: ASTM A536
- Japanese: JIS G5502
- International: ISO 1083
SG Iron Microstructure & Chemistry
Ductile iron is not a single material, but a family of materials that can be produced to offer a wide range of properties through control of the microstructure. The primary mechanical properties of ductile iron are determined by the matrix surrounding the graphite nodules: ferrite (soft, ductile) and pearlite (hard, strong).
By controlling the cooling rates and adding trace alloying elements like copper, nickel, or tin, our foundry can customize the matrix to achieve the exact balance of tensile strength, elongation, and wear resistance required by the OEM application.
Magnesium Inoculation
Tightly monitored magnesium treatment ensures spherical nodule shape.
Alloying Controls
Precise copper additions stabilizer pearlitic matrix for hardness.
Ductile Iron Equivalent Grades Matrix
| EN 1563 Grade | ASTM A536 Grade | ISO 1083 Grade | JIS G5502 Grade |
|---|---|---|---|
| EN-GJS-350-22 | - | 350-22 | FCD 350-22 |
| EN-GJS-400-15 | 65-45-12 | 400-15 | FCD 400-15 |
| EN-GJS-500-7 | 80-55-06 | 500-7 | FCD 500-7 |
| EN-GJS-600-3 | 80-55-06 | 600-3 | FCD 600-3 |
| EN-GJS-700-2 | 100-70-03 | 700-2 | FCD 700-2 |
Ductile Iron Grades Questions Answered
EN-GJS-400-15 is a highly ferritic grade offering superior ductility (15% elongation) and impact resistance. EN-GJS-500-7 has a mixed ferritic-pearlitic matrix, providing higher tensile strength (500 MPa) but lower ductility (7% elongation).
Silicon acts as a ferrite stabilizer, increasing yield strength. Carbon must be maintained around 3.5% to 3.8% to ensure proper graphite nodule formation. Elements like copper or manganese can be added to increase pearlitic content and hardness.
The closest ASTM equivalent of EN-GJS-600-3 is ASTM A536 Grade 80-55-06, which requires a minimum tensile strength of 552 MPa, yield strength of 379 MPa, and 6% elongation.
Yes, we perform various heat treatments including annealing (to increase ductility/ferrite), normalizing (to increase pearlite/tensile strength), and stress relieving (to remove residual casting stresses).
Pearlitic grades (like EN-GJS-700-2 or ASTM 100-70-03) offer high wear resistance, high hardness, and high yield strength, making them ideal for gears, rollers, and crankshafts.
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