Aluminum 339.0
AA 339.0 · UNS A03390
339.0 (UNS A03390) is an Al-Si-Cu-Mg-Ni permanent mold piston alloy in the ANSI/AA 3xx.x family, offered in F, T5, T6 and T7; nickel and copper additions raise high-temperature strength and wear resistance.
Reference datasheet — 339.0 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the T5 condition
339.0 tempers and conditions
339.0 is supplied in 4 conditions, soft to hard. T5 is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Untreated permanent-mold castings; used only where cost matters more than hot strength or dimensional stability. | 140 | 215 | 1.5 | 80 HB | 29 % IACS |
Solution heat treated and overaged (stabilized) | Overaged for maximum dimensional stability and creep resistance in long, hot service; strength drops relative to T5/T6. | 195 | 240 | 1.5 | 90 HB | 30 % IACS |
T5Default Cooled from hot working and artificially aged | Standard production condition for permanent-mold pistons: best combination of hot strength, dimensional stability and cost (no solution treatment/quench distortion). | 234 | 276 | 1 | 100 HB | 28 % IACS |
Solution heat treated and artificially aged | Choose when maximum room-temperature strength and hardness are needed; adds quench distortion risk and cost, and hot-strength advantage over T5 is small. | 255 | 295 | 1 | 115 HB | 27 % IACS |
What is 339.0?
339.0 (UNS A03390) is an Al-Si-Cu-Mg-Ni permanent mold piston alloy in the ANSI/AA 3xx.x family, offered in F, T5, T6 and T7; nickel and copper additions raise high-temperature strength and wear resistance. It is specified for gravity-die cast automotive pistons and hot engine hardware, with 234 MPa yield, 276 MPa tensile, 100 HB, 120 W/m·K and the highest service temperature in this group at 250 °C. Elongation is 1 % and the machinability score is 40 because of abrasive primary Si and Ni-aluminides; 332.0 or 331.0 are used where 250 °C capability is not required. 339.0 has a density of 2.73 g/cm³ (0.0986 lb/in³), heavier than 61% of aluminum grades. It melts at 505°C (941 °F). 339.0 has a yield strength of 234 MPa (33.9 ksi) and a tensile strength of 276 MPa (40 ksi) — stronger than 61% of aluminum grades. Elongation at break is 1% and the elastic modulus is 81 GPa (11.7 Msi).
What is 339.0 used for?
- Automotive pistons
- High-temperature engine components
- Diesel piston crowns
- Compressor and pump pistons
- Turbocharged-engine cast hardware
- Wear surfaces running hot
Advantages
- Low embodied carbon — 9 kg CO₂/kg, better than 99% of aluminum grades
- High service temperature — 250°C (482 °F), better than 97% of aluminum grades
- Stiff — 81 GPa (11.7 Msi), better than 96% of aluminum grades
Limitations
- Limited ductility — 1%, worse than 95% of aluminum grades
- Needs corrosion protection — 32/100, worse than 94% of aluminum grades
- Limited formability — 5/100, worse than 94% of aluminum grades
- Low fracture toughness — 15 MPa·√m (13.7 ksi·√in), worse than 93% of aluminum grades
- Difficult to weld — 22/100, worse than 83% of aluminum grades
339.0 properties
Typical room-temperature values for 339.0-T5; bars are the position among aluminum grades.
Physical3
339.0 has a density of 2.73 g/cm³ (0.0986 lb/in³), heavier than 61% of aluminum grades. It melts at 505°C (941 °F).
Mechanical12
339.0 has a yield strength of 234 MPa (33.9 ksi) and a tensile strength of 276 MPa (40 ksi) — stronger than 61% of aluminum grades. Elongation at break is 1% and the elastic modulus is 81 GPa (11.7 Msi).
Thermal6
339.0 is rated for continuous service to 250°C (482 °F). It conducts heat at 120 W/m·K (69.3 BTU/hr·ft·°F), worse than 80% of aluminum grades. Thermal expansion is 19.4 µm/m·K (10.8 µin/in·°F).
Electrical3
339.0 conducts electricity at 28 % IACS, worse than 82% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), worse than 94% of aluminum grades.
Sustainability4
Producing a kilogram of 339.0 takes about 150 MJ of energy and emits 9 kg of CO₂ — less than 97% of aluminum grades. Typical recycled content is 60%.
Manufacturability8
339.0's machinability is fair (40/100, worse than 81% of aluminum grades); weldability poor (22/100); formability not recommended (5/100).
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. 339.0 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 339.0
Is 339.0 easy to machine?
Abrasive primary Si and Ni-aluminides demand PCD or diamond-coated carbide, high speed with low feed and flood coolant; finish-machine after aging for dimensional stability.
Can 339.0 be welded?
Poor fusion weldability (2–3 % Cu plus low solidus → hot cracking and porosity); repair only with 4145/4047 filler under preheat, or use mechanical joints.
Can 339.0 be formed, bent or molded?
Permanent-mold (gravity die) casting alloy with good fluidity and low shrinkage; grain refine/modify the melt, degas well, and use directional chilling on piston crowns.
339.0 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 | 11 – 13 | 12 |
| Cu | 1.5 – 3 | 2.3 |
| Mg | 0.5 – 1.5 | 1 |
| Niraises elevated-temperature strength | 0.5 – 1.5 | 1 |
| Feimpurity limit | ≤ 1.2 | |
| Mn | ≤ 0.5 | |
| Zn | ≤ 1 | |
| Others (each) | ≤ 0.05 | |
| Others (total) | ≤ 0.15 | |
| Al | balance |
What surface finishes work on 339.0?
Decorative anodizing is poor (dark, mottled); use hard anodize or ferrous-oxalate/graphite coatings on crowns and skirts, tin plating for break-in, or chromate-free primer plus paint elsewhere.
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).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Aluminum 339.0 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A03390
How much does 339.0 cost?
339.0 is a standard-cost aluminum ($$), cheaper than about 71% 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.
339.0 — frequently asked
What is 339.0 used for?
339.0 is typically used for automotive pistons, high-temperature engine components, diesel piston crowns, compressor and pump pistons, turbocharged-engine cast hardware and wear surfaces running hot. In short: highest service temperature here; ni-bearing piston alloy; very abrasive to tooling.
What is the yield strength of 339.0?
339.0 has a typical yield strength of 234 MPa (33.9 ksi) and a tensile strength of 276 MPa (40 ksi) — stronger than 61% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is 339.0 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 81% of aluminum grades). Abrasive primary Si and Ni-aluminides demand PCD or diamond-coated carbide, high speed with low feed and flood coolant; finish-machine after aging for dimensional stability.
Can 339.0 be welded?
Not readily — weldability is rated poor (22/100). Poor fusion weldability (2–3 % Cu plus low solidus → hot cracking and porosity); repair only with 4145/4047 filler under preheat, or use mechanical joints.
What surface finishes work on 339.0?
Decorative anodizing is poor (dark, mottled); use hard anodize or ferrous-oxalate/graphite coatings on crowns and skirts, tin plating for break-in, or chromate-free primer plus paint elsewhere.
Can 339.0 be formed, bent or molded?
Permanent-mold (gravity die) casting alloy with good fluidity and low shrinkage; grain refine/modify the melt, degas well, and use directional chilling on piston crowns.
What is the maximum service temperature of 339.0?
339.0 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 339.0-T5 and 339.0-F?
T5 is the default condition — standard production condition for permanent-mold pistons: best combination of hot strength, dimensional stability and cost (no solution treatment/quench distortion). F: untreated permanent-mold castings; used only where cost matters more than hot strength or dimensional stability. Yield strength is 234 MPa in T5 versus 140 MPa in F.
How much does 339.0 cost?
339.0 is a standard-cost aluminum ($$), cheaper than about 71% 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.
Sources
- Registration Record of Aluminum Association Alloy Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot ("Pink Sheets") — Aluminum Association (2018)
- ASTM B108 / B26 — Aluminum-Alloy Permanent Mold and Sand Castings — ASTM International (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- ASM Handbook Vol. 13 — Corrosion — ASM International (2005)
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.