Aluminum 328.0
AA 328.0 · UNS A03280 · also SC82A
328.0 (UNS A03280, SC82A) is an Al-Si-Cu-Mg sand-casting alloy used as-cast (F) or in T6 for medium-strength general engineering castings.
Reference datasheet — 328.0 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 T6 condition
328.0 tempers and conditions
328.0 is supplied in 2 conditions, soft to hard. T6 is the default FabDigit quotes; the values on this page are for it.
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 |
T6Default 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?
328.0 (UNS A03280, SC82A) is an Al-Si-Cu-Mg sand-casting alloy used as-cast (F) or in T6 for medium-strength general engineering castings. It offers 148 MPa yield, 234 MPa tensile, 75 HB, a 71 GPa elastic modulus and 126 W/m·K thermal conductivity, with good fluidity that suits housings, brackets and hardware poured in sand. Elongation is only 1% and the scored weldability of 35 and corrosion resistance of 40 reflect the copper content, so painted or conversion-coated service is normal; 356.0/A356.0 is the alternative where welding, ductility or marine corrosion resistance governs. 328.0 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). 328.0 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).
What is 328.0 used for?
- housings
- brackets
- marine hardware
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 properties
Typical room-temperature values for 328.0-T6; bars are the position among aluminum grades.
Physical3
328.0 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 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 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 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 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'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. 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. 328.0 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 328.0
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.
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 |
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.
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 328.0 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A03280
- Trade names
- SC82A
How much does 328.0 cost?
328.0 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.
328.0 — frequently asked
What is 328.0 used for?
328.0 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?
328.0 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 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 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?
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 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?
328.0 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.
How much does 328.0 cost?
328.0 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) — 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; 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.