Aluminum 712
AA 712 · UNS A07120 · EN AlZn5Mg · also ZG61A
712.0 is an Al–Zn–Mg sand-casting alloy (nominally ~5.8 % Zn, 0.6 % Mg, 0.5 % Cr) that develops most of its strength by natural aging at room temperature over a few weeks, so useful properties are obtained in the as-cast (F) condition without solution treatment or quenching — an advantage for large, complex or thin-walled castings that would distort in heat treatment.
712 tempers and conditions
712 is supplied in 4 conditions, soft to hard.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Cooled from hot working and naturally aged | Self-aging Al-Zn-Mg sand casting alloy 712.0 in the as-cast, naturally aged T1 condition — develops near-T5 strength without solution treatment, with good machinability and dimensional stability. | 170 | 240 | 4 | 75 HB | 35 % IACS |
As fabricated | Standard supply condition: strength develops by self-aging over ~2–4 weeks at room temperature, no solution treatment or quench needed. | 172 | 240 | 5 | 75 HB | 40 % IACS |
Cooled from hot working and artificially aged | Choose when the natural-aging waiting period is unacceptable or dimensional stability before machining is required; a short low-temperature age gives essentially the naturally aged property level. | 175 | 240 | 4 | 78 HB | 39 % IACS |
Solution heat treated and artificially aged | Rarely supplied — 712.0 is specified as a self-aging alloy, so full solution treatment plus quench is normally avoided because it removes the alloy's main advantage and risks distortion; use only against a customer-specific spec with qualification testing. | 215 | 275 | 3 | 90 HB | 38 % IACS |
What is 712?
712.0 is an Al–Zn–Mg sand-casting alloy (nominally ~5.8 % Zn, 0.6 % Mg, 0.5 % Cr) that develops most of its strength by natural aging at room temperature over a few weeks, so useful properties are obtained in the as-cast (F) condition without solution treatment or quenching — an advantage for large, complex or thin-walled castings that would distort in heat treatment. It offers good machinability, good general corrosion resistance and dimensional stability, and can be anodized or welded reasonably well. Limits are modest fluidity and a tendency to hot-tear (essentially sand-casting only), sensitivity to stress-corrosion cracking in the high-strength direction, and a slow strength build-up that must be allowed for in production scheduling. 712 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 600°C (1,112 °F). 712 has a yield strength of 172 MPa (24.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 55% of aluminum grades. Elongation at break is 5% and the elastic modulus is 71 GPa (10.3 Msi).
What is 712 used for?
- Decorative castings
- Hardware
- Light brackets
Advantages
- Easy to machine — 72/100, better than 80% of aluminum grades
Limitations
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
712 properties
Typical room-temperature values; bars are the position among aluminum grades.
Physical3
712 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 600°C (1,112 °F).
Mechanical10
712 has a yield strength of 172 MPa (24.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 55% of aluminum grades. Elongation at break is 5% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
712 is rated for continuous service to 120°C (248 °F). It conducts heat at 159 W/m·K (91.9 BTU/hr·ft·°F), better than 74% of aluminum grades. Thermal expansion is 23.6 µm/m·K (13.1 µin/in·°F).
Electrical3
712 conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), better than 57% of aluminum grades.
Sustainability4
Producing a kilogram of 712 takes about 195 MJ of energy and emits 12 kg of CO₂ — less than 86% of aluminum grades. Typical recycled content is 50%.
Manufacturability6
712's machinability is very good (72/100, better than 80% of aluminum grades); weldability good (60/100).
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 aluminum family
Yield strength against density for every aluminum grade FabDigit runs. 712 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 712
Is 712 easy to machine?
Machines well with sharp carbide or PCD tooling, high speed and light feed; free-flowing chips, good surface finish, and it holds size well because no quench stresses are present.
Can 712 be welded?
Fair-to-good with GTAW/GMAW using 5356 or 5183 filler; the Zn–Mg matrix re-ages naturally so strength recovers near the weld, but keep heat input low to limit hot cracking and porosity.
Can 712 be formed, bent or molded?
Sand casting is the practical route — fluidity is only moderate and the alloy is hot-tear sensitive, so use generous fillets, directional solidification and chills; avoid permanent-mould/die casting.
Manufacturability
The process limits FabDigit applies to 712. Every 712 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better72 / 100 |
|---|---|
| ISO material group | N.1 |
| Cutting speed (rough / finish) | 350 / 420 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 8× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
712 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 |
|---|---|---|
| Si | ≤ 0.3 | |
| Fe | ≤ 0.5 | |
| Cu | ≤ 0.25 | |
| Mn | ≤ 0.1 | |
| Mg | 0.5 – 0.65 | 0.58 |
| Cr | 0.4 – 0.6 | 0.5 |
| Zn | 5 – 6.5 | 5.8 |
| Tigrain refiner | 0.15 – 0.25 | 0.2 |
| Others (each)0.20 total max | ≤ 0.05 | |
| Al | balance |
What surface finishes work on 712?
Anodizes well (clear or hard coat) and takes chromate/conversion coatings and paint; polish to a moderate lustre only, since sand-cast porosity limits mirror finishes.
Surface treatments FabDigit runs on aluminum 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).
Passivation
Conversion Coating
PVD Coating
Equivalent designations
Standards and trade names that resolve to Aluminum 712 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A07120
- EN / DIN / Werkstoff-Nr.
- AlZn5Mg
- Trade names
- ZG61A
How much does 712 cost?
712 is a budget-cost aluminum ($), cheaper than about 82% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
712 — frequently asked
What is 712 used for?
712 is typically used for decorative castings, hardware and light brackets. In short: cast Al-Zn-Mg.
What is the yield strength of 712?
712 has a typical yield strength of 172 MPa (24.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 55% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is 712 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines well with sharp carbide or PCD tooling, high speed and light feed; free-flowing chips, good surface finish, and it holds size well because no quench stresses are present.
Can 712 be welded?
Yes — weldability is rated good (60/100). Fair-to-good with GTAW/GMAW using 5356 or 5183 filler; the Zn–Mg matrix re-ages naturally so strength recovers near the weld, but keep heat input low to limit hot cracking and porosity.
What surface finishes work on 712?
Anodizes well (clear or hard coat) and takes chromate/conversion coatings and paint; polish to a moderate lustre only, since sand-cast porosity limits mirror finishes.
Can 712 be formed, bent or molded?
Sand casting is the practical route — fluidity is only moderate and the alloy is hot-tear sensitive, so use generous fillets, directional solidification and chills; avoid permanent-mould/die casting.
What is the maximum service temperature of 712?
712 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 712 cost?
712 is a budget-cost aluminum ($), cheaper than about 82% 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 712?
Yes — 712 is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot (Pink Sheets) — The Aluminum Association (2018)
- ASTM B26/B26M — Aluminum-Alloy Sand Castings — ASTM (2018)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- ASM Handbook Vol.15 — Casting — ASM International (2008)
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.