Aluminum Die Casting Alloy Comparison: A380, ADC12, A383, A360, A413, A356

Overview

Aluminum high-pressure die casting (HPDC) draws on a small family of near-eutectic Al-Si-Cu alloys. Each alloy is tuned for a different compromise between fluidity, strength, corrosion resistance, machinability and die-filling behaviour. Specifying the wrong alloy is rarely obvious at qualification — it shows up later as premature gate cracking, failed salt-spray testing, or porosity that cannot be welded out.

This reference consolidates the six alloys most often requested by design engineers — A380, ADC12, A383, A360, A413 and A356 — into one comparable table. ADC12 is the Japanese Industrial Standard (JIS) analogue of the A383 family and dominates Asian supply chains; A356 is included because it is the natural upgrade path when a die-cast part needs strength and elongation that HPDC alloys cannot reach, even though it is normally cast by permanent mold or sand and heat treated.

The values below are representative nominal/designation ranges and typical as-cast mechanical properties. Confirm against the controlling specification (NADCA, ASTM B85, JIS H5302) before release.

Composition and Mechanical Properties

Alloy	Si %	Cu %	Mg %	Fe max %	Tensile MPa	Yield MPa	Elong %	Density g/cm3	Typical use
A380	7.5-9.5	3.5-4.5	≤0.10	1.3 (2.0 des)	320	160	3-4	2.71	General HPDC, brackets, housings
ADC12	9.6-12.0	1.5-3.5	≤0.30	1.3	310	150	1-3	2.70	Asian-supply HPDC, thin walls
A383	9.5-11.5	2.0-3.0	≤0.10	1.3	300	150	2-3	2.70	Complex dies, hard-to-fill shapes
A360	9.0-10.0	≤0.60	0.40-0.60	1.3	320	170	3-5	2.68	Corrosion-resistant, pressure-tight
A413	11.0-13.0	≤1.0	≤0.10	1.3	280	140	3-4	2.66	High fluidity, very thin sections
A356	6.5-7.5	≤0.20	0.25-0.45	0.6	310 (T6)	230 (T6)	6-10	2.69	Structural, heat treated (T5/T6)

Reading the Table

Silicon (Si) drives fluidity and hot-tearing resistance. Higher Si improves die fill and reduces shrinkage but lowers machinability and can raise the tendency for silicon segregation. A413 (11-13% Si) fills the thinnest sections; A380 offers a more balanced 7.5-9.5%.

Copper (Cu) raises strength and hardness and improves machinability, but it reduces corrosion resistance and ductility. A380’s 3.5-4.5% Cu is the reason it is strong yet less salt-spray friendly than A360. Low-copper alloys (A360, A413, A356) are chosen when corrosion resistance matters.

Magnesium (Mg) enables precipitation hardening. A356’s 0.25-0.45% Mg is what allows T5/T6 heat treatment to lift yield to ~230 MPa and elongation to 6-10%. HPDC alloys keep Mg low because magnesium picks up hydrogen porosity readily in the die-casting environment.

Iron (Fe) is an impurity-controlled element. It prevents die soldering but forms brittle Al-Fe-Si platelets; the “design” maximum (2.0% for A380) is used when soldering is a risk, while the stricter 1.3% limit is preferred for mechanical properties.

Density is near-constant at ~2.7 g/cm3 across the family. Aluminum selection is therefore about properties and castability, not weight — see Aluminum vs Magnesium vs Zinc for the weight-vs-strength trade against magnesium and zinc.

How to use this reference

Start from the failure mode: if corrosion or pressure tightness dominates, prefer A360 or A356. If strength and low cost dominate, A380.
Match supply: if your tool shop quotes ADC12, treat it as the A383 family and verify the Cu band (1.5-3.5%) meets your strength need.
For thin-wall (<1.2 mm) parts, move toward A413 or ADC12 for fluidity.
When the part must carry structural load with high elongation, leave HPDC and specify A356 by permanent mold or sand with T5/T6 heat treatment — see Heat Treatment of Castings.
Download the CSV in the Downloads section to build a first-pass material spec sheet.

References

NADCA Product Specification Standards for Die Castings — https://www.diecasting.org/
ASTM B85 / B85M, Standard Specification for Aluminum-Alloy Die Castings
JIS H5302, Aluminum alloy die castings