Aluminum 308.0
AA 308.0 · UNS A03080 · BS LM21
308.0 is an Al-Si-Cu permanent-mold casting alloy (UNS A03080) strengthened by roughly 4–5% copper together with silicon, and is normally used as-cast in the F temper, including sand-cast F.
Reference datasheet — 308.0 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 F condition
308.0 tempers and conditions
308.0 is supplied in 2 conditions, soft to hard. F 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 |
|---|---|---|---|---|---|---|
F | Choose for larger or low-volume sand-cast parts; slower solidification gives coarser structure and 10–20% lower strength than chill casting. | 105 | 170 | 1 | 65 HB | 32 % IACS |
FDefault As fabricated | Standard commercial condition: permanent-mold cast and used as-cast for general-purpose machined castings. | 110 | 195 | 2 | 70 HB | 33 % IACS |
What is 308.0?
308.0 is an Al-Si-Cu permanent-mold casting alloy (UNS A03080) strengthened by roughly 4–5% copper together with silicon, and is normally used as-cast in the F temper, including sand-cast F. It is specified for general-purpose castings, housings and brackets where casting fluidity, 142 W/m·K thermal conductivity and a machinability rating of 72 matter more than ductility. F-temper values are 110 MPa yield, 195 MPa tensile and 2% elongation, with service to about 200 °C. The copper content lowers corrosion resistance and makes fusion welding hot-crack prone, so 356.0 is the usual alternative when weldability or elongation is required. 308.0 has a density of 2.79 g/cm³ (0.101 lb/in³), heavier than 77% of aluminum grades. It melts at 521°C (970 °F). 308.0 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 81% of aluminum grades. Elongation at break is 2% and the elastic modulus is 71 GPa (10.3 Msi).
What is 308.0 used for?
- general castings
- housings
- brackets
Advantages
- High service temperature — 200°C (392 °F), better than 90% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
Limitations
- Hard to polish — 40/100, worse than 91% of aluminum grades
- Limited ductility — 2%, worse than 87% of aluminum grades
- Low fracture toughness — 17 MPa·√m (15.5 ksi·√in), worse than 83% of aluminum grades
- Low strength — 110 MPa (16 ksi), worse than 81% of aluminum grades
- Needs corrosion protection — 38/100, worse than 79% of aluminum grades
308.0 properties
Typical room-temperature values for 308.0-F; bars are the position among aluminum grades.
Physical3
308.0 has a density of 2.79 g/cm³ (0.101 lb/in³), heavier than 77% of aluminum grades. It melts at 521°C (970 °F).
Mechanical13
308.0 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 81% of aluminum grades. Elongation at break is 2% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
308.0 is rated for continuous service to 200°C (392 °F). It conducts heat at 142 W/m·K (82 BTU/hr·ft·°F), better than 51% of aluminum grades. Thermal expansion is 21.5 µm/m·K (11.9 µin/in·°F).
Electrical3
308.0 conducts electricity at 33 % IACS, worse than 57% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (38/100), worse than 79% of aluminum grades.
Sustainability4
Producing a kilogram of 308.0 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 80%.
Manufacturability7
308.0's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (30/100).
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. 308.0 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 308.0
Is 308.0 easy to machine?
Machines freely with sharp PCD or coated carbide tooling; the eutectic Si is abrasive, so use high speed, moderate feed and flood coolant for good surface finish.
Can 308.0 be welded?
Poor fusion weldability — the 4–5% Cu promotes hot cracking; repairs are usually made with 4043/4145 filler under strict preheat control or by mechanical fastening.
Can 308.0 be formed, bent or molded?
Permanent-mold (gravity chill) casting alloy with excellent fluidity and low hot-tear tendency; also castable in sand. Not a wrought alloy — no cold forming.
308.0 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 | 5 – 6 | 5.5 |
| Cu | 4 – 5 | 4.5 |
| Fe | ≤ 1 | |
| Mn | ≤ 0.5 | |
| Mg | ≤ 0.1 | |
| Zn | ≤ 1 | |
| Ti | ≤ 0.25 | |
| Others (each)each | ≤ 0.05 | |
| Others (total)total | ≤ 0.35 | |
| Al | balance |
What surface finishes work on 308.0?
Anodizing gives dark, non-decorative films; prefer chromate/conversion coating plus paint or powder coat, or electroless nickel for wear and corrosion protection.
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 308.0 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A03080
- BS
- LM21
How much does 308.0 cost?
308.0 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.
308.0 — frequently asked
What is 308.0 used for?
308.0 is typically used for general castings, housings and brackets. In short: free-machining cast aluminum; high-fluidity permanent-mold alloy; low-cost general-purpose casting.
What is the yield strength of 308.0?
308.0 has a typical yield strength of 110 MPa (16 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 81% of aluminum grades. Strength varies by condition: see the 2 listed tempers.
Is 308.0 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines freely with sharp PCD or coated carbide tooling; the eutectic Si is abrasive, so use high speed, moderate feed and flood coolant for good surface finish.
Can 308.0 be welded?
Not readily — weldability is rated poor (30/100). Poor fusion weldability — the 4–5% Cu promotes hot cracking; repairs are usually made with 4043/4145 filler under strict preheat control or by mechanical fastening.
What surface finishes work on 308.0?
Anodizing gives dark, non-decorative films; prefer chromate/conversion coating plus paint or powder coat, or electroless nickel for wear and corrosion protection.
Can 308.0 be formed, bent or molded?
Permanent-mold (gravity chill) casting alloy with excellent fluidity and low hot-tear tendency; also castable in sand. Not a wrought alloy — no cold forming.
What is the maximum service temperature of 308.0?
308.0 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 308.0-F and 308.0 F-SAND?
F is the default condition — standard commercial condition: permanent-mold cast and used as-cast for general-purpose machined castings. F-SAND: choose for larger or low-volume sand-cast parts; slower solidification gives coarser structure and 10–20% lower strength than chill casting. Yield strength is 110 MPa in F versus 105 MPa in F-SAND.
How much does 308.0 cost?
308.0 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 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)
- BS 1490 LM21 — Aluminium and aluminium alloy ingots and castings — BSI (1988)
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.