| Element | % |
|---|---|
| Carbon (C) | 3.5–3.9 |
| Silicon (Si) | 2.5–2.8 |
| Manganese (Mn) | ≤0.3 |
| Magnesium (Mg) | 0.03–0.05 |
| Property | Value |
|---|---|
| Tensile strength | 414 MPa (60 ksi) min |
| Yield strength | 276 MPa (40 ksi) min |
| Elongation | 18% min |
| Hardness | 143–187 HB |
Density: 7.1 g/cm³ · Heat treatment: Annealed (ferritic) for maximum ductility and impact toughness.
| Standard | Equivalent grade |
|---|---|
| EN / ISO | EN-GJS-400-18 |
| GB | QT400-18 |
| JIS | FCD400 |
| DIN (old) | GGG40 |
Equivalents by nominal class — confirm exact chemistry & spec for critical parts.
60-40-18 is a softer, ferritic grade with higher elongation (18%) for ductility and impact resistance; 65-45-12 is slightly stronger (65 ksi) with 12% elongation for general structural use. Choose 60-40-18 for pressure/impact, 65-45-12 for general bodies.