AlSi7Mg (A356)
The premier aluminum casting alloy, with excellent fluidity and castability for complex and safety-critical parts.
The A356/AlSi7Mg family is the most important aluminum casting alloy in the world. Its silicon content (6.5–7.5%) provides excellent fluidity for complex mold filling. The A356.2 version has ultra-low iron content (≤0.12%), achieving superior ductility and fatigue life — making it preferred for aluminum wheels and structural automotive components. We manufacture this alloy from both primary and secondary aluminum base depending on customer specifications.
International Nomenclature
| Standard | Designation |
|---|---|
| AA (USA) | A356.0 / A356.2 |
| EN (Europa) | EN AC-42100 · AlSi7Mg0.3 |
| DIN (Alemania) | G-AlSi7Mg / 3.2371 |
| ISO | AlSi7Mg |
| JIS (Japón) | AC4C |
| NF (Francia) | A-S7G03 |
| UNI (Italia) | G-AlSi7Mg |
Chemical Composition
| Element | Symbol | Percentage |
|---|---|---|
| Aluminum | Al | Balance |
| Silicon | Si | 6.50–7.50% |
| Magnesium | Mg | 0.25–0.45% |
| Iron | Fe | ≤0.20% (A356) · ≤0.12% (A356.2) |
| Copper | Cu | ≤0.20% |
| Manganese | Mn | ≤0.10% |
| Zinc | Zn | ≤0.10% |
| Titanium | Ti | ≤0.20% |
Physical Properties
| Property | Value |
|---|---|
| Density | 2.67 g/cm³ |
| Melting Range | 557–615 °C |
| Thermal Conductivity | 149–155 W/m·K |
| Electrical Conductivity | 33–40% IACS |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength (UTS) | ~310 MPa (T6) |
| Yield Strength | ~230 MPa (T6) |
| Elongation | 3–10% (A356.2 T6: 6–10%) |
| Hardness | ~75 HB |
Key Characteristics
- Premier aluminum casting alloy worldwide
- High silicon content (6.5–7.5%) provides excellent fluidity for complex molds
- A356.2 with ultra-low iron (≤0.12%) for safety-critical applications like wheels
- Available with primary aluminum base for maximum purity and ductility
- Low shrinkage during solidification reduces internal defects
- Heat-treatable across multiple tempers (F, T5, T6, T61, T71)
Industries & Applications
Automotive
Aluminum wheels, engine blocks, cylinder heads, suspension components, structural parts
Aerospace
Landing gear components, wing spars, fuselage frames
Defense
Missile components, military vehicle parts
Energy
Turbine components, impellers, industrial installations
Special Notes
The "A" prefix designates a higher purity version. A356.2 enforces ≤0.12% iron, eliminating brittle iron-rich intermetallic phases. This yields ~20% better toughness, with 6–10% elongation vs 2–4% in standard 356. For automotive wheels and safety-critical structural parts, we manufacture A356.2 from primary aluminum base to guarantee low iron and trace content.
Need AlSi7Mg (A356)?
We manufacture this alloy in ingots, donuts, and bars to your exact specifications.