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AlSi7Mg0.6 (A357)

The high-strength version of A356, with higher magnesium for safety-critical automotive structural and aerospace applications.

~345 MPa UTS
6.5–7.5% Silicon (Si)
0.45–0.60% Magnesium (Mg)

A357 (AlSi7Mg0.6) is the premium version of A356, with higher magnesium content (0.45–0.60%) that increases mechanical strength ~15% after T6 heat treatment. It is the preferred alloy for safety-critical automotive structural parts (nodes, shock towers, subframes) and aerospace components. The A357.2 version requires ultra-low iron (≤0.09%), demanding P0610 primary aluminum as the base. We manufacture this alloy exclusively with primary aluminum base.

International Nomenclature

Standard Designation
AA (USA) A357.0 / A357.2
EN (Europa) EN AC-42200 · AlSi7Mg0.6
DIN (Alemania) G-AlSi7Mg0.6 / 3.2372
ISO AlSi7Mg0.6
JIS (Japón) AC4CH

Chemical Composition

ElementSymbolPercentage
Aluminum Al Balance
Silicon Si 6.50–7.50%
Magnesium Mg 0.45–0.60%
Iron Fe ≤0.20% (A357) · ≤0.09% (A357.2)
Copper Cu ≤0.20%
Manganese Mn ≤0.10%
Zinc Zn ≤0.10%
Titanium Ti ≤0.20%
Beryllium Be 0.04–0.07% (opcional)

Physical Properties

Property Value
Density 2.68 g/cm³
Melting Range 557–613 °C
Thermal Conductivity 150–160 W/m·K
Electrical Conductivity 35–40% IACS

Mechanical Properties

Property Value
Tensile Strength (UTS) ~345 MPa (T6)
Yield Strength ~290 MPa (T6)
Elongation 2–5% (A357.2 T6: 5–8%)
Hardness ~100 HB

Key Characteristics

  • High-strength version of A356, with ~15% higher mechanical strength in T6
  • Higher Mg content (0.45–0.60%) vs. A356 (0.25–0.45%) drives mechanical property improvement
  • A357.2 with ultra-low iron (≤0.09%) for superior ductility and fatigue life
  • Requires primary aluminum base (P1020 or P0610) to guarantee low iron content
  • Heat-treatable in T6 and T61 tempers for optimal properties
  • Compatible with strontium (Sr) modification for eutectic refinement

Industries & Applications

Structural Automotive

Structural nodes, shock towers, subframes, safety-critical suspension parts

Aerospace

Aircraft structural components, landing gear parts, turbine housings

Defense

Armored vehicle components, missile structural parts

Special Notes

A357 is identical to A356 except for its higher magnesium content: 0.45–0.60% vs. 0.25–0.45%. This increase achieves UTS of ~345 MPa vs. ~310 MPa in T6. The A357.2 version requires Fe ≤0.09% (even more restrictive than A356.2's ≤0.12%), so we manufacture this alloy exclusively from P0610 primary aluminum base. It is the preferred alloy of OEMs like VW/Audi for next-generation structural automotive parts.

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Legal disclaimer: The technical information, chemical compositions, mechanical and physical properties presented on this website are for illustrative and reference purposes only. Actual values may vary depending on manufacturing conditions, heat treatment, and customer process. Transformación Puebla does not guarantee that the data shown here corresponds exactly to the specifications of a particular batch. For guaranteed specifications, please request the technical data sheet and analysis certificate corresponding to your order.