A357 Aluminum Casting Alloy

Designations: A357.0 · UNS A13570 · EN AC-42200 (AlSi7Mg0.6)A357 is a premium aluminum–silicon–magnesium casting alloy: the same 7% silicon base as A356, with more magnesium and a small beryllium addition for higher strength after T6 heat treatment. It is specified where castings carry structural loads and must be pressure-tight, such as housings, brackets and fittings in defense and industrial equipment. Kormax casts A357 to order for customers in the United States and Canada.

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Chemical Composition

A357 Aluminum Casting Alloy — chemical composition, % by weight
Element	Symbol	Range / limit %
Silicon	Si	6.5–7.5
Magnesium	Mg	0.40–0.70
Iron	Fe	0.20 max
Copper	Cu	0.20 max
Manganese	Mn	0.10 max
Zinc	Zn	0.10 max
Titanium	Ti	0.04–0.20
Beryllium	Be	0.04–0.07
Others, each / total	—	0.05 / 0.15 max
Aluminum	Al	Balance

Mechanical Properties

A357 Aluminum Casting Alloy — mechanical properties
Property	Metric	Imperial
Tensile Strength, typical (T6)	350 MPa	51 ksi
Yield Strength, typical (T6)	270 MPa	39 ksi
Elongation, typical (T6)	4%	4%
Hardness (Brinell), typical (T6)	100 HB	100 HB

Composition to Aluminum Association A357.0. Mechanical properties are typical values in the T6 condition, not specified minima; minima depend on the casting process and specification (ASTM B26 sand, B108 permanent mold).

Comparable and Related Specifications

The standards and grades below may have similar composition, properties or applications, but they should not be treated as direct equivalents without review. Chemistry, heat treatment, toughness requirements and testing provisions can differ between standards.