Aluminum 328.0-T6
Temper · default condition
AA 328.0 · UNS A03280 · also SC82A
T6 = solution heat treated and artificially aged
Standard condition for medium-strength load-bearing sand castings; maximum strength and hardness at the cost of ductility.
Values for the T6 condition
Other 328.0 tempers and conditions
328.0 is listed in 2 conditions; see the grade overview at 328.0.
- F
- T6
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Pick for low-cost, dimensionally stable general castings where medium strength is not required. | 96 | 172 | 1 | 48 HB | 29 % IACS |
T6DefaultThis page Solution heat treated and artificially aged | Standard condition for medium-strength load-bearing sand castings; maximum strength and hardness at the cost of ductility. | 148 | 234 | 1 | 75 HB | 31 % IACS |
What is 328.0-T6?
328.0-T6 is 328.0 in the T6 temper — standard condition for medium-strength load-bearing sand castings; maximum strength and hardness at the cost of ductility. 328.0-T6 has a yield strength of 148 MPa (21.5 ksi) and a tensile strength of 234 MPa (33.9 ksi) — weaker than 67% of aluminum grades. Elongation at break is 1% and the elastic modulus is 71 GPa (10.3 Msi). 328.0-T6 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 521°C (970 °F).
Advantages
- High service temperature — 175°C (347 °F), better than 83% of aluminum grades
Limitations
- Limited ductility — 1%, worse than 95% of aluminum grades
- Limited formability — 5/100, worse than 94% of aluminum grades
- Hard to polish — 40/100, worse than 91% of aluminum grades
- Needs corrosion protection — 40/100, worse than 75% of aluminum grades
328.0-T6 properties
Typical room-temperature values for 328.0-T6; 16 are specific to this condition. Other listed values are 328.0 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
328.0-T6 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 521°C (970 °F).
Mechanical11
328.0-T6 has a yield strength of 148 MPa (21.5 ksi) and a tensile strength of 234 MPa (33.9 ksi) — weaker than 67% of aluminum grades. Elongation at break is 1% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
328.0-T6 is rated for continuous service to 175°C (347 °F). It conducts heat at 126 W/m·K (72.8 BTU/hr·ft·°F), worse than 70% of aluminum grades. Thermal expansion is 22 µm/m·K (12.2 µin/in·°F).
Electrical3
328.0-T6 conducts electricity at 31 % IACS, worse than 68% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), worse than 75% of aluminum grades.
Sustainability4
Producing a kilogram of 328.0-T6 takes about 185 MJ of energy and emits 11.5 kg of CO₂ — less than 90% of aluminum grades. Typical recycled content is 70%.
Manufacturability7
328.0-T6's machinability is good (60/100, worse than 51% of aluminum grades); weldability fair (35/100); formability not recommended (5/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 328.0-T6
Is 328.0 easy to machine?
Machines well with carbide tooling and high speeds; copper-bearing matrix gives short chips, but eutectic/primary Si is abrasive — use PCD for volume production and flood coolant.
Can 328.0 be welded?
Fusion welding is only fair — copper content makes the alloy hot-crack sensitive; use 4043/4145 filler, preheat 150–200 °C and re-solution/age critical repairs.
Can 328.0 be formed, bent or molded?
Sand-casting alloy with good fluidity and feeding; degas and grain-refine/Sr-modify the melt, and use risers on heavy sections to avoid shrinkage porosity.
What surface finishes work on 328.0?
Chromate conversion or primer/paint is the practical protection; decorative anodizing gives a dark grey mottled film due to Si and Cu, and plating requires a zincate pretreatment.
328.0 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 | 7.5 – 8.5 | 8 |
| Cu | 1 – 2 | 1.5 |
| Mgprovides Mg2Si age-hardening in T6 | 0.2 – 0.6 | 0.4 |
| Mn | 0.2 – 0.6 | 0.4 |
| Fe | ≤ 1 | — |
| Zn | ≤ 1.5 | — |
| Cr | ≤ 0.35 | — |
| Ni | ≤ 0.25 | — |
| Ti | ≤ 0.25 | — |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
328.0-T6 — frequently asked
What is 328.0-T6 used for?
328.0-T6 is typically used for housings, brackets and marine hardware. In short: medium-strength sand-casting alloy; good fluidity, moderate cost; copper-bearing, paint-protected service.
What is the yield strength of 328.0-T6?
328.0-T6 has a typical yield strength of 148 MPa (21.5 ksi) and a tensile strength of 234 MPa (33.9 ksi) — weaker than 67% of aluminum grades. Strength varies by condition: see the 2 listed tempers.
Is 328.0-T6 easy to machine?
Reasonably — machinability is rated good (60/100, worse than 51% of aluminum grades). Machines well with carbide tooling and high speeds; copper-bearing matrix gives short chips, but eutectic/primary Si is abrasive — use PCD for volume production and flood coolant.
Can 328.0-T6 be welded?
With care — weldability is rated fair (35/100). Fusion welding is only fair — copper content makes the alloy hot-crack sensitive; use 4043/4145 filler, preheat 150–200 °C and re-solution/age critical repairs.
What surface finishes work on 328.0-T6?
Chromate conversion or primer/paint is the practical protection; decorative anodizing gives a dark grey mottled film due to Si and Cu, and plating requires a zincate pretreatment.
Can 328.0-T6 be formed, bent or molded?
Sand-casting alloy with good fluidity and feeding; degas and grain-refine/Sr-modify the melt, and use risers on heavy sections to avoid shrinkage porosity.
What is the maximum service temperature of 328.0-T6?
328.0-T6 is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 328.0-T6 and 328.0-F?
T6 is the default condition — standard condition for medium-strength load-bearing sand castings; maximum strength and hardness at the cost of ductility. F: pick for low-cost, dimensionally stable general castings where medium strength is not required. Yield strength is 148 MPa in T6 versus 96 MPa in F.
Sources
- Registration Record of Aluminum Association Alloy Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot (Pink Sheets) — The Aluminum Association (2018)
- ASTM B26/B26M — Standard Specification for Aluminum-Alloy Sand Castings — ASTM International (2018)
- 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)
- Aluminum casting alloy property tables (328.0-F / 328.0-T6) — MatWeb / AA typical data (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.