A380 is the most widely specified aluminum die casting alloy in the world, an aluminum-silicon-copper grade holding 7.5 to 9.5% silicon and 3.0 to 4.0% copper. As cast it reaches 324 MPa tensile strength, 159 MPa yield strength, 3.5% elongation and 80 HB hardness, with excellent castability, the best machinability of the common die casting alloys and the lowest relative cost.
A380 is the most widely specified aluminum die casting alloy in the world, an aluminum-silicon-copper grade holding 7.5 to 9.5% silicon and 3.0 to 4.0% copper. As cast it reaches 324 MPa tensile strength, 159 MPa yield strength, 3.5% elongation and 80 HB hardness, with excellent castability, the best machinability of the common die casting alloys and the lowest relative cost.
The copper is what makes A380 both attractive and limited. Copper raises strength and hardness and improves machinability by helping chips break cleanly, but it also lowers corrosion resistance: A380 rates only fair in salt spray or persistent condensation and needs powder coating, paint or a chromate conversion coating for outdoor service. For an indoor housing, a gearbox case or a heavily machined bracket, that trade-off costs nothing.
Specify A380 unless there is a specific reason not to. CharMax Precision casts A380 on cold chamber machines from 160 to 1,250 tons for part weights of 20 g to 12 kg, with spectrometer verification of every ingot lot. Where a part needs better corrosion resistance or pressure tightness we move to A360, and where walls fall below 1.5 mm over a long flow path we move to ADC12.
| ASTM designation | A380 / 380.0 (ASTM B85, UNS A03800) |
|---|---|
| Equivalent grades | ADC10 (JIS), EN AC-46000, YL112 (GB) |
| Ultimate tensile strength | 324 MPa (47 ksi) |
| Yield strength (0.2% offset) | 159 MPa (23 ksi) |
| Elongation in 50 mm | 3.5% |
| Brinell hardness | 80 HB |
| Silicon content | 7.5-9.5% |
| Copper content | 3.0-4.0% |
| Density | 2.74 g/cm³ |
| Thermal conductivity | 96 W/m·K |
| Melting range | 540-595 °C |
| Machinability | Very good, the best of the common die casting alloys |
A380 is an aluminum-silicon-copper die casting alloy standardised in ASTM B85 as alloy 380.0, carrying the UNS number A03800 and the chemical designation AlSi8Cu3Fe. Silicon between 7.5 and 9.5% provides fluidity and low solidification shrinkage, copper between 3.0 and 4.0% provides strength and machinability, and iron held near 1% stops the melt from soldering to the die steel.
A380 is a casting alloy only. It is supplied as remelt ingot, melted at 660 to 700 °C and injected into a hardened steel die; it is never extruded or rolled, and there is no bar stock equivalent. Its published properties are as-cast properties, because high pressure die castings are not solution heat treated. That is the fundamental difference between A380 and a wrought alloy such as 6061, which gets its strength from working the metal and then heat treating it.
A380 and its close national equivalents account for the majority of aluminum die castings produced worldwide. That volume has practical consequences: ingot is available everywhere at the lowest price of any common grade, the process window is wide enough to be forgiving in production, and die life in A380 is long and predictable at 80,000 to 150,000 shots.
The composition below is the ASTM B85 specification for alloy 380.0. Each element is there for a reason, and the ones that look like contamination are usually deliberate: iron in particular is added rather than removed, because a melt that is too clean chemically attacks the die steel.
| Element | Min % | Max % | Function in the alloy |
|---|---|---|---|
| Silicon (Si) | 7.5 | 9.5 | Provides fluidity and cuts solidification shrinkage; the reason the alloy fills thin sections at all |
| Copper (Cu) | 3.0 | 4.0 | Raises tensile strength and hardness and improves machinability; the main reason corrosion resistance is only fair |
| Iron (Fe) | — | 1.3 | Prevents the melt soldering to the die steel; above 1.3% it forms brittle Al5FeSi needles that cut ductility |
| Manganese (Mn) | — | 0.50 | Converts needle-shaped iron phases into a rounded form that is far less damaging to ductility |
| Magnesium (Mg) | — | 0.10 | Restricted in A380; magnesium raises strength through Mg2Si but reduces ductility and increases dross |
| Nickel (Ni) | — | 0.50 | Tolerated from secondary feedstock; adds a little strength at elevated temperature |
| Zinc (Zn) | — | 3.0 | Generously tolerated so secondary ingot stays economical; adds strength but worsens corrosion resistance |
| Tin (Sn) | — | 0.35 | Residual from recycled feedstock; limited because it depresses strength and corrosion performance |
| Others, total | — | 0.50 | Combined allowance for residual elements not individually specified |
| Aluminum (Al) | Balance | Balance | Base metal, typically 80 to 88% of the alloy |
The casting specification permits up to 2.0% iron, but we buy ingot to the 1.3% limit and aim for 0.9 to 1.1% in the furnace, which protects the die without embrittling the casting. Every incoming ingot lot is verified on an optical emission spectrometer before it enters the melt, and lots stay traceable to the casting batch.
The figures below are typical as-cast values measured on separately cast test bars. They are the right numbers for comparing alloys, but they are not the numbers to design a highly loaded part against without discussion: properties inside a real casting vary with wall thickness and local solidification rate, and heavy sections typically test 10 to 15% below test-bar values.
The number that constrains design most often is elongation. At 3.5% in 50 mm, A380 is a low-ductility material. It carries load well and machines well, but it does not tolerate features that bend, crimp or snap during assembly, and it should not be used where a part is expected to deform rather than fracture under overload.
| Property | Value | Notes |
|---|---|---|
| Ultimate tensile strength | 324 MPa (47 ksi) | Separately cast test bar, as-cast condition |
| Yield strength (0.2% offset) | 159 MPa (23 ksi) | Design working stress should sit well below this |
| Elongation in 50 mm | 3.5% | Low ductility; avoid bent tabs, crimps and snap features |
| Shear strength | 186 MPa (27 ksi) | Relevant to cast-in bosses carrying fastener load |
| Fatigue strength | 138 MPa (20 ksi) | R.R. Moore rotating beam, 5 × 10⁸ cycles |
| Modulus of elasticity | 71 GPa | Roughly one third that of steel, so stiffness comes from geometry |
| Brinell hardness | 80 HB | 500 kg load, 10 mm ball |
| Density | 2.74 g/cm³ | The heaviest of the common die casting alloys, due to copper |
| Melting range | 540-595 °C | Solidus to liquidus, a 55 °C freezing range |
| Thermal conductivity | 96 W/m·K | Lower than A360's 113 W/m·K because copper in solution scatters heat carriers |
| Coefficient of thermal expansion | 22.0 µm/m·°C | Measured 20 to 100 °C; matters when bolting to steel |
| Electrical conductivity | 23% IACS | Enough for grounding paths and inherent EMI shielding |
Values follow published NADCA and ASTM data for alloy 380.0 and match the master alloy comparison used across this site. Request a material certificate for lot-specific chemistry and mechanical results.
A380 ingot is the cheapest and most widely available die casting feedstock, the process window is wide enough to keep scrap low, and long die life spreads tooling cost over more parts. On a like-for-like geometry it is normally the least expensive alloy to buy in production quantities.
The 3.0 to 4.0% copper hardens the matrix enough that chips break instead of smearing, so drilled and tapped holes come out clean and machined faces hold ±0.02 mm without built-up edge problems. If a part has heavy machining after casting, A380 is the cheapest alloy to cut.
At 7.5 to 9.5% silicon with a 55 °C freezing range, A380 fills reliably across a wide band of metal temperature and injection velocity. That tolerance is why it survives real production conditions and why die life reaches 80,000 to 150,000 shots.
324 MPa tensile strength at 2.74 g/cm³ gives a better strength-to-weight ratio than steel or zinc. A380 as cast actually exceeds the tensile strength of 6061-T6, although its yield strength and elongation are substantially lower, so the comparison only holds for parts loaded well inside the elastic range.
Because A380 die castings are used as-cast rather than heat treated, there is no solution or ageing step to distort the part. Dimensions coming off the machine are the dimensions you inspect, which makes cast datum features reliable to fixture against for machining.
A380 maps closely onto ADC10 in Japan, EN AC-46000 in Europe and YL112 in China, so a drawing written in any of those systems can normally be produced from the same melt. That keeps supply flexible and avoids requalifying material when a program moves region.
Copper-rich Al2Cu particles set up galvanic cells with the surrounding aluminum, so A380 pits in salt spray, coastal air and persistent condensation. It is not a marine alloy and should not be left bare outdoors. Powder coat, paint or chromate it, or specify A360 where the coating cannot be relied on.
The 7.5 to 9.5% silicon does not anodize, so the film comes out grey, mottled and non-uniform, and copper makes it worse. A380 is not suitable for clear or bright decorative anodizing. Use powder coating for colour and chromate conversion where electrical conductivity must be retained.
3.5% elongation rules out any feature that must deform in service or assembly: no bent tabs, no crimped retainers, no press-in snap fits. Fasten into cast bosses or use inserts instead, and treat overload as a fracture case rather than a yielding case in your analysis.
Gas entrapped during high pressure injection expands at solution temperature and blisters the surface, so T6 is not available on A380 die castings. If your drawing calls for heat-treated properties, the realistic options are a T5 stabilisation, a design change to reduce stress, or a different process.
The same entrapped gas outgasses in the weld pool and produces porous, weak joints with surface blistering. Design in cast bosses for mechanical fasteners, threaded inserts or adhesive joints. If a welded joint is genuinely unavoidable, tell us early so gating and local vacuum assist can be considered.
At 96 W/m·K, A380 conducts heat well compared with steel or plastic but poorly compared with A360 at 113 W/m·K and A413 at 121 W/m·K. For a part whose main job is to move heat, the low-copper grades are worth their price premium.
ADC12 carries more silicon, 9.6 to 12.0% against A380's 7.5 to 9.5%, and that extra eutectic content is what lets it fill thinner walls and longer flow paths. The cost is small but real: tensile strength drops to 310 MPa, hardness to 75 HB, and the higher silicon is more abrasive to cutting tools, which is why ADC12 rates good rather than very good for machinability. Choose ADC12 when walls fall below 1.5 mm, when the flow path is long, or when the supply chain is aligned to Asian JIS grades.
A360 caps copper at 0.6% maximum and adds 0.4 to 0.6% magnesium. Removing the copper moves corrosion resistance from fair to good and pressure tightness from good to excellent, and lifts thermal conductivity from 96 to 113 W/m·K. Note that A360 has a higher yield strength than A380, 170 MPa against 159 MPa, even though its ultimate tensile strength is slightly lower at 317 MPa: magnesium strengthens through Mg2Si, which raises the onset of permanent deformation. The trade-offs are that A360 is harder to cast, machines less freely without copper to break chips, and costs more.
In practice the decision is short. Default to A380. Move to ADC12 for thin walls, and to A360 when the part must survive outdoors, hold pressure, or dissipate heat.
| Property | A380 (AlSi8Cu3Fe) | ADC12 (A383) | A360 (AlSi10Mg) | A413 (AlSi12) |
|---|---|---|---|---|
| Ultimate tensile strength | 324 MPa (47 ksi) | 310 MPa (45 ksi) | 317 MPa (46 ksi) | 296 MPa (43 ksi) |
| Yield strength (0.2%) | 159 MPa (23 ksi) | 150 MPa (22 ksi) | 170 MPa (25 ksi) | 145 MPa (21 ksi) |
| Elongation in 50 mm | 3.5% | 3.5% | 3.5% | 2.5% |
| Brinell hardness | 80 HB | 75 HB | 75 HB | 80 HB |
| Silicon content | 7.5-9.5% | 9.6-12.0% | 9.0-10.0% | 11.0-13.0% |
| Copper content | 3.0-4.0% | 1.5-3.5% | 0.6% max | 1.0% max |
| Density | 2.74 g/cm³ | 2.70 g/cm³ | 2.63 g/cm³ | 2.66 g/cm³ |
| Thermal conductivity | 96 W/m·K | 96 W/m·K | 113 W/m·K | 121 W/m·K |
| Castability | Excellent | Excellent | Very good | Excellent |
| Corrosion resistance | Fair | Fair | Good | Good |
| Machinability | Very good | Good | Good | Fair |
| Pressure tightness | Good | Good | Excellent | Excellent |
| Relative cost | Lowest | Low | Moderate | Moderate |
Properties are typical as-cast values measured on separately cast test bars and will vary with wall thickness, gating and section geometry. Request a material certificate for lot-specific values.
A380 suits any part where mechanical function, machining and piece price matter more than corrosion exposure or maximum thermal performance. That covers most industrial castings, which is why it is the default specification on the majority of drawings we quote.
A380 machines predictably with uncoated or TiAlN-coated carbide at high surface speed, flood coolant and generous chip clearance. The silicon is abrasive enough that tool wear is faster than in 6061, so we run polycrystalline diamond tooling on high-volume programs where insert changes drive cycle cost. Threads cut cleanly in cast bosses, and reamed or bored holes hold H7 fits.
Leave 0.5 to 1.0 mm of machining stock on faces that will be cut, and define cast datum features that a fixture can locate on repeatably. Machining exposes subsurface porosity if it is present, so tell us which faces are machined and which must be pressure tight before tooling design starts, and gating can be arranged to keep porosity out of those areas.
ADC12 is better for thin walls. Its 9.6 to 12.0% silicon puts it closer to the aluminum-silicon eutectic than A380's 7.5 to 9.5%, so a larger fraction of the metal is still liquid late in solidification and can feed thin sections. In practice A380 is comfortable down to 2.0 mm and workable at 1.5 mm, while ADC12 is our normal choice below 1.5 mm and can reach 1.0 mm on small parts with short flow paths. The governing variable is flow length divided by wall thickness rather than thickness alone, so we confirm either alloy with fill simulation before cutting steel.
A380 has a typical as-cast ultimate tensile strength of 324 MPa (47 ksi), with 159 MPa (23 ksi) yield strength at 0.2% offset, 3.5% elongation in 50 mm and 80 HB Brinell hardness. Those figures come from separately cast test bars; inside a real casting, heavy sections and areas fed through long flow paths typically test 10 to 15% lower. For load-bearing parts, send the drawing with the load case and we will advise where the geometry rather than the alloy is the limiting factor.
A380 has fair corrosion resistance, which is adequate indoors and inadequate for sustained outdoor or coastal exposure without a coating. The reason is the 3.0 to 4.0% copper: copper-rich Al2Cu particles form galvanic couples with the aluminum matrix and drive pitting in salt spray and condensation. For sheltered indoor service, shot-blasted A380 is fine as it is. For outdoor equipment, specify powder coating or chromate conversion, or move to A360, where copper is capped at 0.6% maximum and corrosion resistance is rated good.
A380 can be anodized but the result is cosmetically poor. Silicon does not convert to an oxide film, so at 7.5 to 9.5% silicon the coating comes out grey and mottled rather than clear, and copper darkens it further. Hard anodizing for wear resistance is technically possible but thin and uneven. For colour and corrosion protection on die cast A380 we recommend powder coating, and for a conductive corrosion barrier we recommend chromate conversion coating. If bright anodized appearance is a requirement, the part should be machined from wrought 6061 instead.
They are close equivalents rather than identical specifications. A380 is the ASTM B85 grade, ADC10 is the JIS H 5302 grade and EN AC-46000 (AlSi9Cu3(Fe)) is the EN 1706 grade; all three are aluminum-silicon-copper die casting alloys with roughly 8 to 10% silicon and 2 to 4% copper. The differences are in the permitted ranges for silicon, magnesium and zinc. For most housings and brackets they are interchangeable, but if your drawing specifies EN AC-46000 and you are relying on the magnesium or zinc limits, we cast to the EN chemistry and certify to it rather than substituting standard A380 ingot.
No. T6 requires solution treatment near 500 °C, and the gas entrapped during high pressure injection expands at that temperature and blisters the casting surface. This applies to all high pressure die castings, not just A380. The workable alternatives are a T5 stabilisation treatment at lower temperature to relieve stress and stabilise dimensions, selecting a higher-strength alloy, redesigning the section to reduce stress, or switching to a permanent mold or squeeze casting process where heat treatment is viable. We will raise this during DFM review if a drawing calls for a heat-treated condition.
A380 die casting wins on cost above roughly 1,000 parts per year; 6061 machining wins below that and wins on properties throughout. A380 as cast reaches 324 MPa tensile against 310 MPa for 6061-T6, but 6061-T6 has 276 MPa yield strength against 159 MPa and around 8 to 12% elongation against 3.5%, plus far better anodizing and corrosion behaviour. Die casting also brings thin walls, cast-in ribs and fins that are slow to machine. The honest rule is that low volume, tight tolerance or cosmetic anodized parts belong in machined 6061, and production volumes with complex geometry belong in cast A380.
Porosity is controlled at three stages: melt preparation with degassing and filtration, die design with engineered overflows, vents and gate geometry validated by flow simulation, and process control with logged shot profiles and die temperatures. Where parts must be pressure tight or heavily machined in critical areas, we design vacuum assist or use A360 alloy, and verify with leak testing or X-ray inspection.
Send your 2D drawing and 3D model. We will confirm whether A380 is the right alloy for the part, quote piece price and tooling, and return a written DFM report listing any geometry changes that would reduce cost or porosity risk.