Zinc Alloy ZA-12
ASTM ZA-12 · UNS Z35631
ZA-12 is a general-purpose zinc-aluminum casting alloy with 12% aluminum (Z35631, ASTM B669) that balances strength, wear resistance and castability.
Values for the As Cast condition
ZA-12 tempers and conditions
ZA-12 is supplied in 3 conditions, soft to hard. As Cast is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Sand cast, as cast | Choose for large, low-volume or thick-wall parts and bronze-replacement bushings where tooling cost must stay low. | 207 | 290 | 1.5 | 94 HB | 28 % IACS |
Permanent (metal/graphite) mould gravity cast | Medium-volume gravity casting with finer structure than sand: higher yield strength and better surface, moderate tooling cost. | 214 | 310 | 2 | 94 HB | 28.3 % IACS |
As CastDefault general gravity-cast condition (no heat treatment) | Default stocked/quoted condition for ZA-12 castings and ingot; covers typical sand/permanent-mould gravity casting without post-cast heat treatment. | 240 | 310 | 2 | 95 HB | 28 % IACS |
Supply forms, finishes and certifications
Ways ZA-12 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
DC | Cold-chamber pressure die cast | Surface finish |
What is ZA-12?
ZA-12 is a general-purpose zinc-aluminum casting alloy with 12% aluminum (Z35631, ASTM B669) that balances strength, wear resistance and castability. As-cast values are about 240 MPa yield, 310 MPa tensile, 2% elongation and 95 HB, with service to roughly 110 °C and a machinability rating of 80; it is produced by sand, permanent-mould and cold-chamber die casting. Elongation is low, so it suits stiff, wear-loaded parts rather than components that must deform, and it cannot be run on hot-chamber machines. ZA-8 is the alternative when hot-chamber die casting or more ductility is required. ZA-12 has a density of 6.03 g/cm³ (0.218 lb/in³), lighter than 93% of zinc alloy grades. It melts at 377°C (711 °F). ZA-12 has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 310 MPa (45 ksi) — stronger than 71% of zinc alloy grades. Elongation at break is 2% and the elastic modulus is 83 GPa (12 Msi).
What is ZA-12 used for?
- Conveyor components
- Industrial bushings
- Gear and sprocket blanks
- Machine frames and brackets
- Pump and valve housings
- Wear plates and guide rails
- Tooling and fixture bodies
Limitations
- Limited ductility — 2%, worse than 100% of zinc alloy grades
- Low stiffness — 83 GPa (12 Msi), worse than 93% of zinc alloy grades
- Limited formability — 10/100, worse than 92% of zinc alloy grades
ZA-12 properties
Typical room-temperature values for ZA-12-As Cast; bars are the position among zinc alloy grades.
Physical3
ZA-12 has a density of 6.03 g/cm³ (0.218 lb/in³), lighter than 93% of zinc alloy grades. It melts at 377°C (711 °F).
Mechanical14
ZA-12 has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 310 MPa (45 ksi) — stronger than 71% of zinc alloy grades. Elongation at break is 2% and the elastic modulus is 83 GPa (12 Msi).
Thermal6
ZA-12 is rated for continuous service to 110°C (230 °F). It conducts heat at 116 W/m·K (67 BTU/hr·ft·°F), better than 86% of zinc alloy grades. Thermal expansion is 24.2 µm/m·K (13.4 µin/in·°F).
Electrical3
ZA-12 conducts electricity at 28 % IACS, better than 75% of zinc alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), better than 50% of zinc alloy grades.
Sustainability4
Producing a kilogram of ZA-12 takes about 60 MJ of energy and emits 3.6 kg of CO₂ — more than 93% of zinc alloy grades. Typical recycled content is 25%.
Manufacturability8
ZA-12's machinability is very good (80/100, better than 64% of zinc alloy grades); weldability poor (20/100); formability not recommended (10/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the zinc alloy family
Yield strength against density for every zinc alloy grade FabDigit runs. ZA-12 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZA-12
Is ZA-12 easy to machine?
Machines very freely with sharp carbide or HSS tooling, high speeds, light rake and minimal lubricant; excellent surface finish and long tool life.
Can ZA-12 be welded?
Essentially not fusion-welded in production; repairs are made by zinc-based filler/soldering or adhesive bonding, with low heat input to avoid melting the 377 °C solidus.
Can ZA-12 be formed, bent or molded?
Foundry alloy — sand, permanent-mould and cold-chamber die casting (pour ~450–500 °C); good fluidity and thin-wall fill, allow for solidification shrinkage and avoid hot-chamber machines.
Manufacturability
The process limits FabDigit's quote engine applies to ZA-12. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Excellent80 / 100 |
|---|---|
| Cutting speed (rough / finish) | — / — |
| Minimum wall | — |
| Minimum internal radius | — |
| Drill depth limit | |
| Best surface (machined / polished) | Ra — / — |
| Hardenable after machining | — |
ZA-12 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Al | 10.5 – 11.5 | 11 |
| Cu | 0.5 – 1.25 | 0.9 |
| Mg | 0.02 – 0.03 | 0.02 |
| Femax (0.05 max for ingot) | ≤ 0.08 | |
| Pb | ≤ 0.01 | |
| Cd | ≤ 0.01 | |
| Sn | ≤ 0 | |
| Znbalance, high-grade zinc | balance |
What surface finishes work on ZA-12?
Not anodizable; use chromate/phosphate conversion coats, Cu-Ni-Cr electroplate, powder or wet paint; polishes to a bright finish but needs a protective topcoat outdoors.
Surface treatments FabDigit runs on zinc alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Zinc Alloy ZA-12 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- Z35631
- Similar grades
- B669
How much does ZA-12 cost?
ZA-12 is a standard-cost zinc alloy ($$), cheaper than about 81% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ZA-12 — frequently asked
What is ZA-12 used for?
ZA-12 is typically used for conveyor components, industrial bushings, gear and sprocket blanks, machine frames and brackets, pump and valve housings and wear plates and guide rails. In short: high-strength ZA casting.
What is the yield strength of ZA-12?
ZA-12 has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 310 MPa (45 ksi) — stronger than 71% of zinc alloy grades. Strength varies by condition: see the 3 listed tempers.
Is ZA-12 easy to machine?
Yes — machinability is rated very good (80/100, better than 64% of zinc alloy grades). Machines very freely with sharp carbide or HSS tooling, high speeds, light rake and minimal lubricant; excellent surface finish and long tool life.
Can ZA-12 be welded?
Not readily — weldability is rated poor (20/100). Essentially not fusion-welded in production; repairs are made by zinc-based filler/soldering or adhesive bonding, with low heat input to avoid melting the 377 °C solidus.
What surface finishes work on ZA-12?
Not anodizable; use chromate/phosphate conversion coats, Cu-Ni-Cr electroplate, powder or wet paint; polishes to a bright finish but needs a protective topcoat outdoors.
Can ZA-12 be formed, bent or molded?
Foundry alloy — sand, permanent-mould and cold-chamber die casting (pour ~450–500 °C); good fluidity and thin-wall fill, allow for solidification shrinkage and avoid hot-chamber machines.
What is the maximum service temperature of ZA-12?
ZA-12 is rated for continuous use to about 110°C (230 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ZA-12 As Cast and ZA-12-SC?
As Cast is the default condition — default stocked/quoted condition for ZA-12 castings and ingot; covers typical sand/permanent-mould gravity casting without post-cast heat treatment. SC: choose for large, low-volume or thick-wall parts and bronze-replacement bushings where tooling cost must stay low. Yield strength is 240 MPa in As Cast versus 207 MPa in SC.
How much does ZA-12 cost?
ZA-12 is a standard-cost zinc alloy ($$), cheaper than about 81% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in ZA-12?
Yes — ZA-12 is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B791 — Zinc-Aluminum (ZA) Alloy Foundry and Die Castings — ASTM International (2019)
- ASTM B669 — Zinc-Aluminum Alloy in Ingot Form for Foundry and Die Castings — ASTM International (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Zinc and Zinc Alloys) — ASM International (1990)
- ZA-12 alloy data sheet — Eastern Alloys (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.