Al-Si-Cu Casting Alloy

380 (A380)

The most requested aluminum die casting alloy in North America, excellent combination of castability, strength, and cost.

320–330 MPa UTS
7.5–9.5% Silicon (Si)
3.0–4.0% Copper (Cu)

380 (A380) is the most widely used die casting alloy in North America. With ~8.5% silicon and ~3.5% copper, it offers excellent fluidity, good mechanical strength, and is very economical to produce from secondary aluminum. It is the standard for automotive parts, appliances, and industrial die cast components.

International Nomenclature

Standard Designation
AA (USA) 380.0 / A380.0
EN (Europa) EN AC-46000 · AlSi9Cu3(Fe)
DIN (Alemania) G-AlSi9Cu3 / 3.2163
JIS (Japón) ADC10

Chemical Composition

ElementSymbolPercentage
Aluminum Al Balance
Silicon Si 7.5–9.5%
Copper Cu 3.0–4.0%
Iron Fe ≤2.00% (380) · ≤1.30% (A380)
Zinc Zn ≤3.00%
Manganese Mn ≤0.50%
Magnesium Mg ≤0.10%
Nickel Ni ≤0.50%

Physical Properties

Property Value
Density 2.71 g/cm³
Melting Range 521–593 °C
Thermal Conductivity 96 W/m·K
Electrical Conductivity ~27% IACS

Mechanical Properties

Property Value
Tensile Strength (UTS) 320–330 MPa
Yield Strength 160–175 MPa
Elongation 2.5–3.5%
Hardness ~80 HB

Key Characteristics

  • The most widely used die casting alloy in North America
  • Excellent fluidity and castability for complex thin-wall parts
  • Copper provides good mechanical strength and machinability
  • Very economical due to compatibility with secondary aluminum
  • Tolerant of higher iron levels without significant degradation

Compared to Similar Alloys

380 (A380) vs AlSi11Cu2 (A383)

Both are sibling Al-Si-Cu casting alloys (3xx.x series) for high-pressure die casting. The key difference is the Si/Cu balance: 380 carries more copper (3.0–4.0%) and less silicon (7.5–9.5%), favoring strength and cost; AlSi11Cu2/A383 carries more silicon (9.5–11.5%) and less copper (1.5–3.5%), favoring fluidity, thin-wall fill, and better corrosion resistance.

Dimension 380 (A380) AlSi11Cu2 (A383)
Key composition (Si / Cu) Si 7.5–9.5% · Cu 3.0–4.0% (more copper) Si 9.5–11.5% · Cu 1.5–3.5% (more silicon)
Mechanical strength (no heat treatment, as-cast F) UTS 320–330 MPa · yield 160–175 MPa · ~80 HB UTS 310–330 MPa · yield 150–170 MPa · ~85 HB
Casting process High-pressure die casting; excellent castability High-pressure die casting; exceptional fluidity for thin walls
Machinability Good; copper improves machinability Excellent; Si–Cu combination favors machining
Corrosion resistance Lower: higher copper content reduces it Better than 380 due to lower copper (still limited by the Cu present)
Weldability Poor: high copper makes welding difficult (typical of Al-Si-Cu) Poor, though somewhat better than 380 due to lower copper; not a weld-oriented alloy
Typical application Transmission cases, engine blocks, brackets, valves (North America standard, ADC10) Thin-wall die cast parts: housings, heat sinks, electronics (global standard, ADC12)

380 (A380): Choose 380 when you need maximum mechanical strength and lowest cost on robust die cast parts (transmissions, blocks, brackets) and corrosion is not critical.

AlSi11Cu2 (A383): Choose AlSi11Cu2/A383 when thin-wall fill and complex geometries are critical, or you want better corrosion resistance and dimensional reproducibility (global ADC12 standard for electronics and housings).

View AlSi11Cu2 (A383) specifications →

Industries & Applications

Automotive

Transmission cases, engine blocks, timing covers, brackets, pump housings

Appliances

Motor housings, frames, structural appliance components

Industrial

Power tools, valves, connectors, machinery equipment

Special Notes

380 is the first choice for die casting in North America. Its higher copper content vs. 383/ADC12 gives it better strength but lower corrosion resistance. The A380 version limits iron to ≤1.30% for better ductility. It is equivalent to Japanese ADC10.

Frequently Asked Questions

What is 380 (A380) alloy and what is it used for?

380 (A380) is an Al-Si-Cu casting alloy and the most widely used die casting alloy in North America. It combines excellent fluidity, good mechanical strength, and low cost, making it the standard for automotive parts (transmission cases, engine blocks, brackets), appliances, and industrial components such as power tools and valves.

What is the chemical composition of 380 and what do its elements contribute?

Its base is aluminum with 7.5–9.5% silicon and 3.0–4.0% copper. Silicon provides the excellent fluidity and castability for complex thin-wall parts; copper provides good mechanical strength and machinability. It also tolerates up to ≤3.00% zinc and relatively high iron levels (≤2.00% in 380, ≤1.30% in A380) without significant degradation.

Which casting process is 380 intended for?

380 is designed primarily for high-pressure die casting, where its excellent fluidity and castability allow filling complex thin-wall parts. Its melting range is 521–593 °C and its density is 2.71 g/cm³, characteristics typical of the 3xx.x aluminum-silicon series.

What mechanical strength does 380 offer, and is it heat-treatable?

In its as-cast condition, 380 reaches a tensile strength of 320–330 MPa, yield strength of 160–175 MPa, elongation of 2.5–3.5%, and ~80 HB hardness. Die-cast 380 is normally used in the as-cast condition and is not heat-treated; copper delivers its good strength directly from casting.

How does 380 compare with 383 (ADC12)?

380 has higher copper content than 383/ADC12, giving it better mechanical strength but lower corrosion resistance. 380 is the first choice for die casting in North America and is equivalent to Japanese ADC10 (EN AC-46000 / AlSi9Cu3(Fe)). The A380 version limits iron to ≤1.30% for better ductility than 380 (≤2.00%).

Can TP produce 380 from recycled aluminum (wheel scrap)?

Yes. A key advantage of 380 is that it is very economical due to its compatibility with secondary aluminum, making it ideal to produce from recycled scrap. Its tolerance of higher iron (≤2.00%) and zinc (≤3.00%) levels makes recycled feedstock easy to use without significant degradation of its properties.

Need 380 (A380)?

We manufacture this alloy in ingots, donuts, and bars to your exact specifications.

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.