MATERIALS/ALLOY SELECTOR
Die-casting alloy selector: eleven zinc and aluminum grades compared
Filter by base metal and requirement, cross-reference ASTM, EN, JIS and GB, and compare composition, mechanical properties, minimum wall — and where each grade fits and where it does not.
Grade comparison table
Mechanical values are typical as-cast figures under the standards listed; the real values move with wall thickness and cooling rate, and the certificate that ships with your order governs. Click a grade for the full write-up.
| Grade | Standards | Composition % | Density g/cm³ | Tensile MPa | Elong. % | Hardness HB | Melting range | Min. wall | Typical use |
|---|---|---|---|---|---|---|---|---|---|
| A360Al | ASTM B85 A360.0 ≈ EN AC-43400 (AlSi10Mg(Fe)) ≈ ADC3 · ≈ GB/T 15115 YZAlSi10Mg | Si 9.0–10.0 · Mg 0.40–0.60 · Fe ≤1.3 · Cu ≤0.6 · Al bal. | 2.63 | 317 | 5 | 75 | 557–596 ℃ | 1.2 mm | Pump bodies, thermostat housings, marine and outdoor equipment, cosmetic castings |
| A380Al | ASTM B85 A380.0 ≈ EN AC-46000 (AlSi9Cu3(Fe)) ≈ ADC10 · ≈ GB/T 15115 YZAlSi9Cu4 | Si 7.5–9.5 · Cu 3.0–4.0 · Fe ≤1.3 · Zn ≤3.0 · Mg ≤0.1 · Al bal. | 2.71 | 324 | 3.5 | 80 | 540–595 ℃ | 1 mm | Engine brackets, pump bodies, motor end covers, gearbox housings |
| ADC6Al | ≈ ASTM B85 518.0 ≈ EN AC-51200 (AlMg9) JIS H5302 ADC6 · ≈ GB/T 15115 YZAlMg5Si1 | Mg 2.5–4.0 · Mn 0.40–0.60 · Si ≤1.0 · Fe ≤0.8 · Cu ≤0.1 · Al bal. | 2.57 | 290 | 8 | 60 | 570–620 ℃ | 1.5 mm | Coastal and chemical-environment parts, decoratively anodised trim, connectors that must deform |
| ADC10Al | ≈ ASTM B85 A380.0 ≈ EN AC-46000 JIS H5302 ADC10 · ≈ GB/T 15115 YZAlSi9Cu4 | Si 7.5–9.5 · Cu 2.0–4.0 · Fe ≤1.3 · Mg ≤0.3 · Zn ≤1.0 · Al bal. | 2.71 | 320 | 3 | 80 | 515–585 ℃ | 1 mm | Motorcycle housings, general-power structural parts, transmission cases |
| ADC12Al | ≈ ASTM B85 A383.0 ≈ EN AC-46500 JIS H5302 ADC12 · ≈ GB/T 15115 YZAlSi11Cu3 | Si 9.6–12.0 · Cu 1.5–3.5 · Fe ≤1.3 · Mg ≤0.3 · Zn ≤1.0 · Al bal. | 2.7 | 310 | 3.5 | 75 | 515–582 ℃ | 0.9 mm | Carburetor bodies, throttle bodies, clutch housings, covers and general housings |
| AlSi12Al | ≈ ASTM B85 A413.0 EN AC-44300 / AC-44100 (AlSi12) ≈ ADC1 · ≈ GB/T 15115 YZAlSi12 | Si 10.5–13.5 · Fe ≤1.0 · Cu ≤0.10 · Mg ≤0.10 · Al bal. | 2.66 | 290 | 3 | 60 | 570–585 ℃ | 0.8 mm | Very thin-wall parts, finned thermal parts, thin pressure-tight housings |
| AlSi9Cu3Al | ≈ ASTM B85 A380.0 EN AC-46000 (AlSi9Cu3(Fe)) ≈ ADC10 · ≈ GB/T 15115 YZAlSi9Cu4 | Si 8.0–11.0 · Cu 2.0–4.0 · Fe ≤1.3 · Zn ≤1.2 · Mg 0.05–0.55 · Al bal. | 2.75 | 320 | 3 | 80 | 510–600 ℃ | 1 mm | Gearbox covers, oil-pump housings, structural mounts, engine ancillary housings |
| Zamak 3Zn | ASTM B86 AG40A (Zamak 3) EN 1774 ZP0400 / ZL0400 ≈ JIS H5301 ZDC2 · ≈ GB/T 13818 ZZnAl4 | Al 3.9–4.3 · Mg 0.03–0.06 · Cu ≤0.25 · Zn bal. | 6.6 | 283 | 10 | 82 | 381–387 ℃ | 0.5 mm | Smart-lock panels, locks, bathroom hardware, sensor housings, trim |
| Zamak 5Zn | ASTM B86 AC41A (Zamak 5) EN 1774 ZP0410 / ZL0410 ≈ JIS H5301 ZDC1 · ≈ GB/T 13818 ZZnAl4Cu1 | Al 3.9–4.3 · Cu 0.7–1.2 · Mg 0.03–0.06 · Zn bal. | 6.6 | 328 | 7 | 91 | 380–386 ℃ | 0.5 mm | Gears, structural hardware, automotive interior parts, wear-facing components |
| ZA-8Zn | ASTM B86 ZA-8 EN 1774 ZP0810 — · ≈ GB/T 13818 ZZnAl8Cu1 | Al 8.0–8.8 · Cu 0.8–1.3 · Mg 0.015–0.030 · Zn bal. | 6.3 | 374 | 8 | 103 | 375–404 ℃ | 0.8 mm | High-load brackets, connectors, load-bearing housings, wear-facing structural parts |
| ZA-12Zn | ASTM B86 ZA-12 EN 1774 ZP1110 — · ≈ GB/T 13818 ZZnAl11Cu1 | Al 10.5–11.5 · Cu 0.5–1.25 · Mg 0.015–0.030 · Zn bal. | 6.03 | 404 | 5 | 100 | 377–432 ℃ | 1.2 mm | Heavy-duty structural parts, bearing sleeves and wear bushings, sliding parts replacing bronze |
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Grade by grade
Each grade is written from the same five angles: composition and standards, properties, behaviour in process, surface finishing, and where it fits or does not. Click a grade to open it.
A360
ALUMINUMASTM B85 A360The best corrosion resistance and pressure tightness of the die-cast aluminums; more ductile than A380 and the right pick for pressure housings and anodised parts.
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A360
ALUMINUMASTM B85 A360The best corrosion resistance and pressure tightness of the die-cast aluminums; more ductile than A380 and the right pick for pressure housings and anodised parts.
Composition and standards
A360 is an Al-Si-Mg alloy: 9.0–10.0% silicon, 0.40–0.60% magnesium and copper capped below 0.6% — and it is that low copper which gives it corrosion resistance clearly better than copper-bearing grades such as A380. The reference standard is ASTM B85 A360.0, with EN AC-43400 (AlSi10Mg(Fe)) as the closest European grade, ADC3 in Japan and YZAlSi10Mg under GB/T 15115. Specify it as "ASTM B85 A360.0" and state the copper ceiling: suppliers often read "A360" loosely and deliver something inside the A380 band.
Properties
Typical as-cast values are about 317 MPa tensile, 165 MPa yield, 3.5–5% elongation and HB 75, at a density of 2.63 g/cm³ and a freezing range of 557–596 ℃. Its value is not in the strength figures but in ductility and soundness: elongation roughly half again that of A380 means the part tolerates press-fitting and light straightening without cracking, while a narrow freezing range feeds well and leaves the casting dense — the precondition for anything that has to hold pressure.
In process
Fluidity is a step below ADC12, so long thin sections leave less margin and we ask for 1.2 mm as a starting minimum wall. The magnesium makes the melt more sensitive to oxidation, so degassing and holding time need watching or inclusion risk rises. Machinability is moderate: silicon is not high but the magnesium phase is sticky, and heavy feeds build up on the edge — diamond or coated carbide tooling at higher speed and lower feed is the usual answer. Pressure-tight parts in A360 are run with local squeeze and leak tested 100%.
Surface finishing
A360 anodises better than any other die-cast aluminum we run: low copper and high magnesium give a relatively even film in silver, black and the usual colours — though a die casting's film still carries a grey cast and cannot be held to an extruded-6063 appearance. Powder coating, wet paint and e-coat all work. For anodised cosmetic parts, agree the visible faces at the DFM stage so gates, ejector pins and weld lines are all routed to the back, and fix a colour-difference criterion up front — we control to ΔE ≤1.0.
Where it fits — and where it does not
Right for: pump bodies, thermostat housings and valve bodies that must hold 0.25 MPa or more; structural parts facing salt spray or the weather; cosmetic parts to be anodised. Wrong for: intricate parts below 1.0 mm wall — use ADC12 or AlSi12; general structural work where cost is the only driver, since both the alloy and the process cost more; and hot, strength-led service, where AlSi9Cu3 is the better answer.
A380
ALUMINUMASTM B85 A380The North-American workhorse — the best balance of strength, castability and cost, with good pressure tightness.
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A380
ALUMINUMASTM B85 A380The North-American workhorse — the best balance of strength, castability and cost, with good pressure tightness.
Composition and standards
A380 is an Al-Si-Cu alloy — 7.5–9.5% silicon with 3.0–4.0% copper, the copper buying strength and machinability. It is ASTM B85 A380.0, with EN AC-46000 (AlSi9Cu3(Fe)) as the European equivalent, ADC10 in Japan and YZAlSi9Cu4 in China. It is the grade most often written on North-American drawings, usually as a bare "A380" with no standard cited; at quotation we confirm whether A380.0 or the low-iron A380.1 is meant, because the iron ceiling changes both die release and downstream machining.
Properties
Typical as-cast: 324 MPa tensile, 160 MPa yield, 3–3.5% elongation, HB 80, density 2.71 g/cm³, freezing range 540–595 ℃. Stronger than A360 but with about half the elongation, it sits at the hard-and-brittle end: fine under static load, but think twice where the part is press-fitted, riveted or takes impact. Thermal conductivity of roughly 96 W/(m·K) is adequate for heat-dissipating parts, though AlSi12 is better.
In process
It casts well and fills consistently, and with iron held around 0.8–1.1% it releases cleanly, making it one of the safest choices for volume structural parts. Copper widens the freezing range slightly, so heavy sections are more prone to shrinkage porosity than A360 and hot spots need squeeze pins or overflows to feed them. Machinability is among the best of the die-cast aluminums — the copper phase breaks chips well and tools last — which suits parts with many bores and a lot of stock to remove.
Surface finishing
At 3–4% copper its corrosion resistance is ordinary and it is not a candidate for decorative anodising — the film comes out dark and patchy with poor colour consistency. The normal route is blasting followed by powder or wet paint; where more protection is needed, e-coat or a chromate-free conversion coating underneath the topcoat. Neutral salt spray of 240–480 h is achievable depending on the system. If a part needs both A380 strength and an anodised appearance, the grade choice itself usually has to be reopened.
Where it fits — and where it does not
Right for: brackets, housings and covers where strength and cost lead and appearance comes from paint; parts with heavy machining. Wrong for: bare parts living in salt spray or damp; cosmetic parts to be decoratively anodised; and features that must deform plastically or be riveted. Pressure-tight parts are feasible in A380, but under the same conditions A360 gives a better first-pass yield.
ADC6
ALUMINUMJIS H5302 ADC6An Al-Mg alloy with the best corrosion resistance, ductility and anodised colour of the group — at the price of difficult casting and higher cost.
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ADC6
ALUMINUMJIS H5302 ADC6An Al-Mg alloy with the best corrosion resistance, ductility and anodised colour of the group — at the price of difficult casting and higher cost.
Composition and standards
ADC6 is one of the few die-cast aluminums built on magnesium rather than silicon: 2.5–4.0% Mg with 0.40–0.60% Mn, silicon and iron both held low and copper effectively excluded. It is JIS H5302 ADC6, with ASTM B85 518.0 as the nearest American grade, EN AC-51200 (AlMg9, at higher magnesium) in Europe and YZAlMg5Si1 in China. It shows up mostly on Japanese drawings, and when a customer names it the reason is almost always anodised appearance or corrosion resistance, not strength.
Properties
Typical as-cast values are around 290 MPa tensile, 150 MPa yield, 5–8% elongation and HB 60, at 2.57 g/cm³ — the lightest aluminum in this table. Elongation is the highest of the die-cast aluminums, so the part will take a degree of bending and riveting. The low hardness cuts the other way: it scratches easily, and cosmetic parts need protection and careful handling between operations.
In process
Casting is where it fights back. Magnesium raises the hot-tearing tendency sharply, the freezing range is wide and fluidity poor, so we ask for 1.5 mm minimum wall and insist on controlled section changes and generous radii. In the furnace, magnesium oxidises and burns off, calling for cover protection and tighter pre-pour composition control — which is why it costs a grade more than ADC12. Machining, by contrast, goes well: low cutting forces and a clean surface, though the material is gummy and needs sharp edges and plenty of coolant.
Surface finishing
Anodising is what it exists for: with silicon and copper both low, the film comes out even and clear, and white, silver and pale colours reach the closest thing to extruded appearance that a die casting can. That is the reason customers accept the casting difficulty. Corrosion resistance is excellent — bare parts usually stand up to coastal service without further coating — and powder, paint and e-coat all work equally well.
Where it fits — and where it does not
Right for: structural parts in coastal, chemical or damp service; cosmetic parts that must be decoratively anodised with consistent colour; connectors that need to deform. Wrong for: thin-wall or deep-cavity geometry, where hot tearing bites; cost-sensitive high-volume general parts; and anything needing high strength or hot service. Where it is chosen, a pilot run to confirm the geometry is worth the time.
ADC10
ALUMINUMJIS H5302 ADC10The Japanese counterpart to A380, with a lower zinc ceiling and a narrower composition band, so lots stay consistent.
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ADC10
ALUMINUMJIS H5302 ADC10The Japanese counterpart to A380, with a lower zinc ceiling and a narrower composition band, so lots stay consistent.
Composition and standards
ADC10 shares the Al-Si-Cu family with A380 — 7.5–9.5% silicon, 2.0–4.0% copper — and the real difference is the zinc ceiling: 1.0% here against 3.0% in A380.0. For parts that must stay dimensionally settled and take coating consistently, that limit earns its keep. It is JIS H5302 ADC10, with A380.0, EN AC-46000 and YZAlSi9Cu4 as the American, European and Chinese equivalents. It is among the most common aluminum grades on Japanese OEM drawings.
Properties
Typical as-cast values — about 320 MPa tensile, 160 MPa yield, 2–3% elongation, HB 80, density 2.71 g/cm³, freezing range 515–585 ℃ — overlap A380 closely enough that the two can be evaluated interchangeably. The practical difference is lot-to-lot: the JIS composition band is narrower, so dimensional behaviour and coating performance drift less across a long production life.
In process
It casts like A380: good fluidity, stable release, comfortable on medium and large housings. Heavy sections carry the same shrinkage tendency and hot spots still need cooling lines and squeeze pins. Machining is easy, with stable bores and threads and long tool life. When we switch a machine between ADC10 and A380 we re-run first article and re-check shrinkage — the two are close but not identical, and die dimensions are set for the specific grade.
Surface finishing
As with A380, the copper content rules out decorative anodising. The normal route is blast, then powder, paint or e-coat. Worth noting that the lower zinc ceiling helps coating adhesion and long-term blistering, which is a genuine plus on painted parts. Where protection has to go further, a conversion coating under the topcoat is the usual step.
Where it fits — and where it does not
Right for: Japanese OEM supply; long-running housings where lot consistency matters; painted cosmetic parts. Wrong for: decorative anodising; bare parts in salt spray, where A360 belongs; very thin walls, where ADC12 flows better. If your drawing says only "aluminum die casting", we quote ADC12 and set out the cost step to ADC10 at the DFM stage.
ADC12
ALUMINUMJIS H5302 ADC12Excellent fluidity and the best cost-performance of any die-cast aluminum; the first choice for thin, complex parts and the grade we run most.
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ADC12
ALUMINUMJIS H5302 ADC12Excellent fluidity and the best cost-performance of any die-cast aluminum; the first choice for thin, complex parts and the grade we run most.
Composition and standards
ADC12 runs 9.6–12.0% silicon and 1.5–3.5% copper, with the silicon close to the eutectic — the root of its fluidity. It is JIS H5302 ADC12, with ASTM B85 A383.0, EN AC-46500 and YZAlSi11Cu3 as the equivalents. It is the grade we pour most and the default whenever a project does not name one: on thin, complex, high-volume parts, nothing else in aluminum offers this combination of filling ability and cost.
Properties
Typical as-cast values: around 310 MPa tensile, 150 MPa yield, 1–3.5% elongation, HB 75, density 2.70 g/cm³, freezing range 515–582 ℃. Strength sits close to A380 and elongation lower — the brittleness that comes with high silicon is the price. Thermal expansion is at the low end for aluminum, around 21×10⁻⁶/K, which helps where the part mates with steel across a wide temperature swing.
In process
It casts better than anything else here: it fills smoothly, freezes over a narrow range, feeds well and releases cleanly, so 0.9 mm walls are achievable and complex ribbing and deep cavities come out first time. The cost lands in machining — the hard silicon phase wears tooling, so tool life on high-volume bore work is shorter than in A380 and PCD or diamond-coated tools at controlled speed are the norm. High silicon also makes exposed porosity more consequential, so pressure-tight parts need a tighter gating and venting window.
Surface finishing
Anodising is not on the menu: at this silicon level the film turns grey and uneven and cosmetic parts fail on colour. Blasting, powder, paint, e-coat and conversion coatings all suit it, and it takes black paint very well — the PWK28 carburetor bodies we run in volume are painted ADC12. If a part must be anodised in colour, the grade should change to A360 or ADC6 at the DFM stage rather than after T1.
Where it fits — and where it does not
Right for: thin complex parts, cost-sensitive volume work, painted cosmetic parts and structural housings — which covers most of what we run. Wrong for: decorative anodising; features needing high elongation or impact resistance; bare parts in prolonged salt spray. As the default grade its real advantage is maturity: we hold long-run data on shrinkage, process window and defect countermeasures, so new projects in ADC12 usually need the fewest trial rounds.
AlSi12
ALUMINUMEN AC-44300A near-eutectic Al-Si alloy: the best fluidity and pressure tightness and the lowest thermal expansion, but soft and hard on tooling.
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AlSi12
ALUMINUMEN AC-44300A near-eutectic Al-Si alloy: the best fluidity and pressure tightness and the lowest thermal expansion, but soft and hard on tooling.
Composition and standards
AlSi12 carries 10.5–13.5% silicon, sitting on the Al-Si eutectic at roughly 12.6%, with copper and magnesium both held under 0.10%. It is EN AC-44300 / AC-44100, with A413.0, ADC1 and YZAlSi12 as equivalents. When a European drawing specifies AlSi12 it is usually after one of two things: the ability to fill an extreme thin wall, or pressure tightness.
Properties
Typical as-cast values: about 290 MPa tensile, 140 MPa yield, 2–3% elongation, HB 60, density 2.66 g/cm³, with eutectic solidification giving an unusually narrow freezing range of roughly 570–585 ℃. Thermal expansion is the lowest of the aluminums at around 20×10⁻⁶/K and conductivity around 120 W/(m·K) beats both ADC12 and A380 — two properties that give it a real edge on thermal parts and on close fits against steel.
In process
A eutectic composition means solidification happens at almost a single temperature: feeding is concentrated, shrinkage porosity is low and it is one of the most pressure-tight aluminums in this table, with walls down to 0.8 mm. The bill comes due in machining — abundant silicon and a soft matrix both wear tooling and raise burrs, so hole edges and threads are harder to hold than in ADC12 and PCD tooling at higher speed with plenty of coolant is normal. That cost belongs in the quotation.
Surface finishing
As with ADC12, high silicon greys the anodised film and rules out decorative colour. Corrosion resistance beats the copper-bearing grades and bare parts hold up acceptably in ordinary service. Blasting, powder, paint and e-coat all suit it. Heat-sink parts are often blasted and powder-coated black to raise radiative dissipation — but film thickness affects thermal performance and should be called out on the drawing.
Where it fits — and where it does not
Right for: 0.8–1.2 mm walls; fins and thermal enclosures; thin pressure-tight housings with modest machining. Wrong for: parts with heavy machining, where tooling cost eats the casting advantage; hard or wear-facing surfaces; decorative anodising. Before choosing it, it is worth asking whether what the casting saves will be handed back in the machine shop.
AlSi9Cu3
ALUMINUMEN AC-46000The European standard grade — good machinability and dimensional stability at temperature, suited to transmission and pressure housings.
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AlSi9Cu3
ALUMINUMEN AC-46000The European standard grade — good machinability and dimensional stability at temperature, suited to transmission and pressure housings.
Composition and standards
AlSi9Cu3(Fe) is the highest-volume die-casting grade in Europe: 8.0–11.0% silicon, 2.0–4.0% copper and a specified 0.05–0.55% magnesium. It belongs to the same family as A380 and ADC10, and the stated magnesium floor is what gives it a slight edge in ageing behaviour and dimensional stability when hot. The standard is EN AC-46000 within EN 1706, with A380.0, ADC10 and YZAlSi9Cu4 as equivalents. On German and Italian drawings it is effectively the default.
Properties
Typical as-cast values span 240–320 MPa tensile, 140–200 MPa yield, under 1% to 3% elongation and HB 80–100, at 2.75 g/cm³ with a freezing range of roughly 510–600 ℃. The band is wide because wall thickness and cooling rate matter: a thin, fast-cooled section can come out more than 20% stronger than a heavy one. We say so plainly when agreeing property requirements with you, or separately cast test-bar data will never reconcile with values cut from the part.
In process
It casts well on medium and large complex housings, and machining is its strongest suit in this table: the copper and magnesium phases break chips short and clean, so bores, faces and threads come out consistently with long tool life. That makes it the first candidate for gearbox covers, oil-pump housings and anything else with a lot of metal to remove. Heavy sections still need cooling and feeding designed around the hot spots, and iron is held at 0.8–1.1% for reliable release.
Surface finishing
It shares the copper-grade limitation: no decorative anodising. The usual route is blast then powder, paint or e-coat. European customers routinely ask for RoHS and REACH declarations and a ban on hexavalent chromium. Neutral salt spray of 240–480 h is achievable depending on the system, with the required hours fixed on the drawing or in the technical agreement.
Where it fits — and where it does not
Right for: housings and covers with heavy machining; European OEM supply; transmission parts needing some hot dimensional stability. Wrong for: decorative anodising; features requiring high elongation; simple, deeply cost-driven parts, where ADC12 is the better buy. For European customers we produce to EN AC-46000 by default and issue a material certificate referencing EN 1706.
Zamak 3
ZINCASTM B86 AG40AThe zinc benchmark: outstanding dimensional stability, the best ductility of the family and the best plating adhesion.
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Zamak 3
ZINCASTM B86 AG40AThe zinc benchmark: outstanding dimensional stability, the best ductility of the family and the best plating adhesion.
Composition and standards
Zamak 3 is the baseline: 3.9–4.3% aluminum, 0.03–0.06% magnesium, balance zinc, with copper held below 0.25%. It is ASTM B86 AG40A, EN 1774 ZP0400, JIS H5301 ZDC2 and GB/T 13818 ZZnAl4. Zinc is unforgiving about impurities — lead, cadmium and tin must each stay at ppm level, or castings suffer intergranular corrosion and crack months later. That is the classic mode of mass failure in zinc parts, and the reason we spectrometer-test every melt.
Properties
Typical values: 283 MPa tensile, 221 MPa yield, 10% elongation, HB 82, density 6.6 g/cm³, melting 381–387 ℃. That 10% elongation is the highest in this table, which means the part can be riveted, bent or crimped without cracking. Dimensional stability beats every aluminum grade here and standard tolerances reach CT4–CT5 — the reason it has no real substitute in locks and precision assemblies. Impact toughness is better than Zamak 5 as well.
In process
It runs hot-chamber, and the low melting point takes tool life to 250k–1M shots, putting the tooling cost per part far below aluminum. Fluidity is excellent: 0.5 mm walls are achievable where the projected area stays under 25 cm², and fine ribbing and small lettering both form. Machining is easy with low cutting forces. One caution: castings shrink slightly as they age at room temperature, so precision assemblies are stabilised for 3–6 hours at 100 ℃ to bring that movement forward.
Surface finishing
Plating is what it is for — chrome, nickel, gold and antique finishes all work, and adhesion is the best in the zinc family, which is why high-end locks and bathroom hardware are almost universally Zamak 3. The decisive work happens at the casting machine, not the plating line: blisters and pitting after plating almost always trace back to sub-surface porosity and release-agent residue in the skin. We route weld lines off the visible faces, keep ejector pins on the back, control die temperature and spray dosage, and inspect appearance 100% before plating.
Where it fits — and where it does not
Right for: plated cosmetic parts; parts that will be riveted, bent or crimped; precision assemblies with tight tolerances; complex, thin, finely detailed geometry. Wrong for: weight-driven applications, at 2.4 times the density of aluminum; sustained service above 100 ℃, where creep sets in; and high-load structural work, where ZA-8 or ZA-12 belongs.
Zamak 5
ZINCASTM B86 AC41AZamak 3 plus about 1% copper: stronger and more wear-resistant, but less ductile — think twice before bending or riveting it.
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Zamak 5
ZINCASTM B86 AC41AZamak 3 plus about 1% copper: stronger and more wear-resistant, but less ductile — think twice before bending or riveting it.
Composition and standards
Zamak 5 differs from Zamak 3 in exactly one respect: copper rises from ≤0.25% to 0.7–1.2%. It is ASTM B86 AC41A, EN 1774 ZP0410, JIS H5301 ZDC1 and GB/T 13818 ZZnAl4Cu1. Impurity control is identical to Zamak 3 — lead, cadmium and tin strictly limited. European customers specify Zamak 5 more often than North American ones, who lean to Zamak 3; that is market habit rather than any technical verdict.
Properties
Typical values: 328 MPa tensile, 269 MPa yield, 7% elongation, HB 91 — roughly 16% more strength and 11% more hardness than Zamak 3, paid for with elongation falling from 10% to 7% and impact toughness with it. That trade has to be settled at design time: **if the part will afterwards be bent, riveted or crimped, choose Zamak 3.** Cracking in those operations is a familiar failure in Zamak 5. Creep resistance, on the other hand, is better, so sustained loads suit it.
In process
Hot-chamber, with essentially the same process window as Zamak 3. Fluidity is marginally lower but not by an amount that matters in practice, and 0.5 mm remains the starting minimum wall. The copper raises casting hardness, so tool wear in machining is a little higher than Zamak 3 while still being easy work. Tool life runs 250k–1M shots. Where one die is used for both grades, shrinkage and first-article dimensions need re-confirming at each changeover.
Surface finishing
Plating performance matches Zamak 3 — chrome, nickel and antique finishes are all routine — and corrosion resistance is marginally better. Worth noting that the higher hardness makes polishing slower, so cosmetic parts carry a little more polishing cost than in Zamak 3; on mirror finishes that difference belongs in the quotation. Painting and e-coat suit it equally.
Where it fits — and where it does not
Right for: load-bearing and wear-facing hardware; gears, slides and other rubbing components; plated cosmetic parts needing more strength than Zamak 3 offers. Wrong for: anything to be bent, riveted or crimped afterwards — use Zamak 3; features with an impact requirement; and cost-sensitive mirror-polished cosmetics.
ZA-8
ZINCASTM B86 ZA-8also called Zamak 8The strongest zinc that can still be cast hot-chamber; approaches aluminum strength and can replace some aluminum structural castings.
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ZA-8
ZINCASTM B86 ZA-8also called Zamak 8The strongest zinc that can still be cast hot-chamber; approaches aluminum strength and can replace some aluminum structural castings.
Composition and standards
ZA-8 raises aluminum to 8.0–8.8% with 0.8–1.3% copper and 0.015–0.030% magnesium. It is ASTM B86 ZA-8, EN 1774 ZP0810 and GB/T 13818 ZZnAl8Cu1, with no direct JIS equivalent. Of the ZA series — ZA-8, ZA-12, ZA-27 — it is the only member that can still be cast hot-chamber, and that matters commercially: ZA-12 and ZA-27 must run cold-chamber, with a different cycle and a different tooling scheme.
Properties
Typical values: 374 MPa tensile, 290 MPa yield, 6–8% elongation, HB 103, density 6.3 g/cm³ — slightly lighter than Zamak 3 and 5. Tensile strength already exceeds most die-cast aluminums while elongation stays at 6–8%, the best strength-toughness combination in this table. Creep resistance and wear resistance both beat Zamak 5, which suits sustained loading. The 375–404 ℃ freezing range is wider than Zamak 3 or 5, so the process window is correspondingly tighter.
In process
It still runs hot-chamber, but the high aluminum content attacks the gooseneck and shot components harder, so maintenance intervals shorten against Zamak 3 or 5 and tool life drops with them, typically to 300k–600k shots. Fluidity is below Zamak 3, so 0.8 mm is the sensible minimum wall. The wider freezing range raises shrinkage tendency in heavy sections, and hot spots need feeding designed the way an aluminum part would be. Machining is straightforward.
Surface finishing
It can be plated, but adhesion and appearance consistency fall short of Zamak 3 and 5: the higher aluminum changes the skin structure and the pre-treatment has to be adjusted, so demanding cosmetic work should be sampled first. Painting, e-coat and passivation all suit it, and corrosion resistance is better than Zamak 3. Used structurally, most customers choose powder or e-coat rather than plating.
Where it fits — and where it does not
Right for: structural parts that need real strength but want zinc's dimensional accuracy and tool life; load-bearing brackets and connectors; replacing some aluminum castings to cut tooling cost. Wrong for: walls under 0.8 mm; demanding plated cosmetics, where Zamak 3 belongs; weight-led designs. Before committing, run a total-cost comparison of a ZA-8 part against the ADC12 alternative — the balance between tooling and piece price often lands counter-intuitively.
ZA-12
ZINCASTM B86 ZA-12also called Zamak 12The strongest ZA grade in common use — outstanding wear and load capacity, but it has to run cold-chamber.
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ZA-12
ZINCASTM B86 ZA-12also called Zamak 12The strongest ZA grade in common use — outstanding wear and load capacity, but it has to run cold-chamber.
Composition and standards
ZA-12 takes aluminum to 10.5–11.5%, with 0.5–1.25% copper and 0.015–0.030% magnesium. It is ASTM B86 ZA-12, EN 1774 ZP1110 and GB/T 13818 ZZnAl11Cu1. The aluminum level is beyond what a hot-chamber machine will tolerate, so it has to run cold-chamber: a slower cycle, a higher piece cost, and the loss of part of the long-tool-life advantage that makes zinc attractive in the first place.
Properties
Typical values: 404 MPa tensile, 320 MPa yield, 4–5% elongation, HB 100, at 6.03 g/cm³ — the highest tensile strength in this table, clearly above every die-cast aluminum. Its most under-used property is self-lubrication and wear behaviour: under sliding friction ZA-12 performs close to tin bronze and can replace some bronze bushings at a real cost advantage. Elongation of 4–5% puts it at the brittle end.
In process
Cold-chamber, with a cycle noticeably slower than hot-chamber work and tool life of roughly 150k–300k shots. The wide 377–432 ℃ freezing range makes heavy sections prone to shrinkage porosity, so feeding and cooling are designed to aluminum standards. Minimum wall is realistically 1.2 mm; thin, intricate geometry is not what it is for. Machining goes well, with stable turned and bored surfaces that suit precision bearing seats.
Surface finishing
Plating is possible but not the natural choice: the high aluminum makes pre-treatment more sensitive and appearance less consistent than Zamak 3. Most applications are functional and use paint, e-coat, or the as-cast surface. Corrosion resistance is good. In bearing use the machined surface is normally left bare, since a coating would disturb both the fit and the friction behaviour.
Where it fits — and where it does not
Right for: heavy-duty structural parts; bushings, sleeves and slides; sliding components replacing tin bronze on cost. Wrong for: thin complex geometry; demanding plated cosmetics; and high-volume small parts where cycle time and cost rule, which belong on hot-chamber Zamak 3, 5 or ZA-8. It is a grade that pays well when chosen correctly and badly when it is not — worth confirming geometry and duty with us before committing.
FURTHER READING
Technical articles
- MATERIALS
ADC12, A380, and A360 Aluminum Alloys: Composition, Performance, and Practical Selection for Die-Cast Parts
Three grades with similar names and similar strength that are still not interchangeable. Composition and properties from NADCA and JIS sources, and what really differs in filling, corrosion, machining and finishing.
- MATERIALS
Zamak 3 vs. Zamak 5: Composition, Performance, and Practical Selection for Zinc Die Castings
The difference is mainly copper. Composition and properties from NADCA data, and what the extra copper trades in strength, ductility, dimensional stability and creep.
- MATERIALS
Zinc Die Casting vs Aluminum Die Casting: How to Choose the Right Material for Your Part
Compare zinc and aluminum die casting by part size, weight, strength, wear, stability, machining, finish, assembly, tooling, and total cost.
- DESIGN RULES
How to Control Minimum Wall Thickness in Aluminum and Zinc Die Casting Product Design
Learn how to control minimum wall thickness in aluminum and zinc die castings, including fillability, ribs, transitions, porosity, machining, tooling, and production capability.
Still not sure which grade?
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