Material Comparison
Compare verified engineering materials side by side with condition-specific mechanical properties.
| Parameter | ASTM A48 Class 40 Gray Cast Iron | EN-GJL-250 Gray Cast Iron |
|---|---|---|
| Material Family | Cast Iron | Cast Iron |
| Subfamily | Gray Cast Iron | Gray Cast Iron |
| ASTM Designation | A48 Class 40 | — |
| UNS Designation | F12801 | — |
| SAE Designation | J431 G4000 | — |
| EN Designation | — | EN-GJL-250 |
| W-Nr Designation | — | EN-JL1040 |
| DIN Designation | — | GG-25 |
| ISO Designation | — | 185/JL/250 |
| Element | ASTM A48 Class 40 Gray Cast Iron | EN-GJL-250 Gray Cast Iron |
|---|---|---|
| C (Carbon) | 2.9 – 3.2% | 3 – 3.35% |
| Si (Silicon) | 1.6 – 2% | 1.8 – 2.2% |
| Mn (Manganese) | 0.7 – 1% | 0.65 – 0.95% |
| P (Phosphorus) | ≤ 0.08% | ≤ 0.12% |
| S (Sulfur) | ≤ 0.12% | ≤ 0.12% |
| Fe (Iron) | — | — |
| Property | ASTM A48 Class 40 Gray Cast Iron | EN-GJL-250 Gray Cast Iron |
|---|---|---|
| Density · TYPICALUnit: g/cm³ | 7.25 g/cm³ | 7.2 g/cm³ |
| Mechanical Parameter | ASTM A48 Class 40 Gray Cast IronAs-Cast (Standard Test Bar B, 30.5 mm diameter) | EN-GJL-250 Gray Cast IronAs-Cast (Wall thickness 15 mm to 30 mm) |
|---|---|---|
| Poisson Ratio · TYPICALUnit: dimensionless | 0.27 dimensionless | 0.26 dimensionless |
| Property | ASTM A48 Class 40 Gray Cast Iron | EN-GJL-250 Gray Cast Iron |
|---|---|---|
| Electrical Resistivity · TYPICALCategory: ELECTRICAL • Unit: nΩ·m | 620 nΩ·m | 660 nΩ·m |
| Thermal Conductivity · TYPICALCategory: THERMAL • Unit: W/(m·K) | 44 W/(m·K) | 46 W/(m·K) |
| Specific Heat Capacity · TYPICALCategory: THERMAL • Unit: J/(kg·K) | 490 J/(kg·K) | 480 J/(kg·K) |
| Coefficient of Thermal Expansion · TYPICALCategory: THERMAL • Unit: µm/(m·K) | 10.8 µm/(m·K) | 11 µm/(m·K) |
Machinability: Good machinability (~70% relative to C36000 baseline). Fully pearlitic matrix requires rigid machine tool setups, coated carbide tooling, and positive rake geometries.
Weldability: Extremely difficult to weld. Fusion welding creates high susceptibility to cracking due to high carbon equivalent. Recommended strictly for casting salvage using qualified hot-box procedures (350°C–400°C preheat).
Formability / Cold Working: Non-deformable. Cannot be rolled or cold formed.
Heat Treatment & Annealing: Stress relief at 565°C–620°C for 2 hours. Induction surface hardening achieves 54–58 HRC for heavy wear surfaces.
Machinability: Good machinability (~85% of C36000 baseline). Fully pearlitic matrix provides clean, burr-free surfaces on machined slideways.
Weldability: Poor weldability. Requires preheating (300°C) and qualified repair procedures to avoid brittle white iron at the fusion line.
Formability / Cold Working: Non-deformable.
Heat Treatment & Annealing: Stress relief at 550°C–600°C for 2 hours to ensure dimensional stability. Slideways can be induction surface hardened to 50–55 HRC.