DIE CASTINGAluminum · Zinc · Dies · Machining · Finishing
Materials
Choosing a die casting alloy
The alloy sets the strength, weight, corrosion behavior, finish options and cost of a casting, and it largely decides the process. Most die castings come from a short list of standard alloys: A380, or ADC12 (the JIS alloy most Asian die casters run, close to A383) for aluminum; Zamak 3 or Zamak 5 for zinc; AZ91D for magnesium. A356 is a gravity and sand casting alloy, used when the part must be heat treated to T6.
In China, ADC12 is supplied as YL113 under GB/T 15115; in Europe the usual counterpart of A380 is EN AC-46000, AlSi9Cu3(Fe). These equivalents are close, not identical, so name the standard on the drawing.
Typical properties of common casting alloys
| Alloy | Process | Density (g/cm³) | Tensile strength (MPa) | Elongation | Notes |
|---|---|---|---|---|---|
| A380 | Die casting | ≈ 2.7 | ≈ 320 | ≈ 3.5% | General-purpose die casting alloy; 3–4% Cu, fair corrosion resistance |
| ADC12 | Die casting | ≈ 2.7 | ≈ 300 | ≈ 2–3% | JIS alloy with more silicon, very good fluidity; close to A383 |
| A356 (T6) | Gravity / sand | ≈ 2.7 | ≈ 230–280 | ≈ 3–8% | Heat treatable, good ductility, weldable |
| Zamak 3 | Hot chamber | ≈ 6.6 | ≈ 280 | ≈ 10% | Most used zinc alloy; stable dimensions, easy to plate |
| Zamak 5 | Hot chamber | ≈ 6.6 | ≈ 330 | ≈ 7% | About 1% Cu; stronger and harder than Zamak 3 |
| AZ91D | Die casting | ≈ 1.8 | ≈ 230 | ≈ 3% | Most used magnesium die casting alloy |
Typical values from published alloy data, measured on separately cast test bars. A real casting depends on wall thickness, porosity and process; use the relevant standard or the supplier data sheet for design values.
Alloy FAQ
Is ADC12 the same as A380?
No. ADC12 (JIS H 5302) has more silicon, about 9.6–12%, and less copper than A380, and is closest to A383. It flows better into thin sections; A380 is slightly stronger in typical data. Many drawings accept either after agreement.
Which alloy is the strongest?
In typical data, Zamak 5 (about 330 MPa) and A380 (about 320 MPa) have the highest tensile strength of the common die casting alloys. Per unit weight, aluminum and magnesium are far ahead of zinc. Compare ductility, creep and corrosion too before choosing.
Which alloy is the lightest?
Magnesium alloys such as AZ91D, at about 1.8 g/cm³, then aluminum at about 2.7 g/cm³ and zinc at about 6.6 g/cm³.