Aluminum 2008-T81
Temper
AA 2008 · UNS A92008
T81 = solution treated, ~2 % cold stretched, then paint-bake aged
The in-service condition of a stamped and painted panel — 170–185 °C / 20–30 min bake raises yield strength by 80–120 MPa for dent resistance.
Values for the T81 condition
Other 2008 tempers and conditions
2008 is listed in 6 conditions; see the grade overview at 2008.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition, used for intermediate processing or extremely severe draws; must be solution treated afterwards to develop strength. | 60 | 130 | 32 | 38 HB | 48 % IACS |
Solution heat treated, pre-aged/stabilized for controlled natural ageing | Mill pre-age (short low-temperature hold) that suppresses room-temperature ageing drift and preserves the paint-bake response over long storage. | 120 | 235 | 29 | 63 HB | 43 % IACS |
T4Default Solution heat treated and naturally aged | Standard as-delivered condition for automotive outer-panel stamping: maximum formability with bake-hardening reserve. | 125 | 240 | 28 | 65 HB | 42 % IACS |
T81This page Solution treated, ~2 % cold stretched, then paint-bake aged | The in-service condition of a stamped and painted panel — 170–185 °C / 20–30 min bake raises yield strength by 80–120 MPa for dent resistance. | 245 | 300 | 15 | 88 HB | 45 % IACS |
T6, heat treated by the user | Same property level as T6 but obtained by heat treating after forming/welding at the fabricator rather than at the mill. | 270 | 310 | 12 | 93 HB | 46 % IACS |
Solution heat treated and artificially aged | Peak-aged condition for parts needing maximum strength after forming; formability is largely exhausted. | 275 | 315 | 12 | 95 HB | 46 % IACS |
What is 2008-T81?
2008-T81 is 2008 in the T81 temper — the in-service condition of a stamped and painted panel — 170–185 °C / 20–30 min bake raises yield strength by 80–120 MPa for dent resistance. 2008-T81 has a yield strength of 245 MPa (35.5 ksi) and a tensile strength of 300 MPa (43.5 ksi) — stronger than 64% of aluminum grades. Elongation at break is 15% and the elastic modulus is 70 GPa (10.2 Msi). 2008-T81 has a density of 2.72 g/cm³ (0.0983 lb/in³), heavier than 57% of aluminum grades. It melts at 560°C (1,040 °F). T4 is the default condition FabDigit quotes; T81 is available on request or by drawing note.
Advantages
- Conducts heat well — 195 W/m·K (112.7 BTU/hr·ft·°F), better than 90% of aluminum grades
- High electrical conductivity — 45 % IACS, better than 86% of aluminum grades
- Ductile — tolerates forming and impact — 15%, better than 82% of aluminum grades
Limitations
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
- Needs corrosion protection — 38/100, worse than 79% of aluminum grades
2008-T81 properties
Typical room-temperature values for 2008-T81; 11 are specific to this condition. Other listed values are 2008 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
2008-T81 has a density of 2.72 g/cm³ (0.0983 lb/in³), heavier than 57% of aluminum grades. It melts at 560°C (1,040 °F).
Mechanical10
2008-T81 has a yield strength of 245 MPa (35.5 ksi) and a tensile strength of 300 MPa (43.5 ksi) — stronger than 64% of aluminum grades. Elongation at break is 15% and the elastic modulus is 70 GPa (10.2 Msi).
Thermal6
2008-T81 is rated for continuous service to 120°C (248 °F). It conducts heat at 195 W/m·K (112.7 BTU/hr·ft·°F), better than 90% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
2008-T81 conducts electricity at 45 % IACS, better than 86% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (38/100), worse than 79% of aluminum grades.
Sustainability4
Producing a kilogram of 2008-T81 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability7
2008-T81's machinability is good (55/100, worse than 59% of aluminum grades); weldability fair (35/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 2008-T81
Is 2008 easy to machine?
Machines like a soft 2000-series-T4 sheet — sharp positive-rake carbide, high speed and flood coolant to avoid built-up edge; chips improve markedly after artificial ageing.
Can 2008 be welded?
Cu-bearing and hot-crack sensitive in fusion welding; join by resistance spot welding, self-piercing rivets, clinching or structural adhesive, with 4043 filler only if arc welding is unavoidable.
Can 2008 be formed, bent or molded?
Stamp in the T4/T4P condition promptly after delivery — high n-value and elongation suit deep-drawn outer panels; allow for continued natural ageing if the coil is stored warm.
What surface finishes work on 2008?
Zr/Ti or chromate-free conversion pretreatment plus e-coat/paint is standard; clear anodizing is only fair (yellow-tinged film) because of the copper.
2008 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 | 0.5 – 0.8 | 0.65 |
| Feimpurity limit | ≤ 0.4 | 0.2 |
| Cumain strengthening addition | 0.7 – 1.1 | 0.9 |
| Mn | ≤ 0.3 | 0.1 |
| Mgwith Si/Cu gives bake-hardening | 0.25 – 0.5 | 0.38 |
| Cr | ≤ 0.1 | — |
| Zn | ≤ 0.25 | — |
| Tigrain refiner | ≤ 0.1 | 0.02 |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
2008-T81 — frequently asked
What is 2008-T81 used for?
2008-T81 is typically used for automotive body panels, closures and stamped sheet parts. In short: bake-hardening body sheet; high-formability 2000-series sheet; spot weld or rivet.
What is the yield strength of 2008-T81?
2008-T81 has a typical yield strength of 245 MPa (35.5 ksi) and a tensile strength of 300 MPa (43.5 ksi) — stronger than 64% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is 2008-T81 easy to machine?
Reasonably — machinability is rated good (55/100, worse than 59% of aluminum grades). Machines like a soft 2000-series-T4 sheet — sharp positive-rake carbide, high speed and flood coolant to avoid built-up edge; chips improve markedly after artificial ageing.
Can 2008-T81 be welded?
With care — weldability is rated fair (35/100). Cu-bearing and hot-crack sensitive in fusion welding; join by resistance spot welding, self-piercing rivets, clinching or structural adhesive, with 4043 filler only if arc welding is unavoidable.
What surface finishes work on 2008-T81?
Zr/Ti or chromate-free conversion pretreatment plus e-coat/paint is standard; clear anodizing is only fair (yellow-tinged film) because of the copper.
Can 2008-T81 be formed, bent or molded?
Stamp in the T4/T4P condition promptly after delivery — high n-value and elongation suit deep-drawn outer panels; allow for continued natural ageing if the coil is stored warm.
What is the maximum service temperature of 2008-T81?
2008-T81 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.
What is the difference between 2008-T4 and 2008-T6?
T4 is the default condition — standard as-delivered condition for automotive outer-panel stamping: maximum formability with bake-hardening reserve. T6: peak-aged condition for parts needing maximum strength after forming; formability is largely exhausted. Yield strength is 125 MPa in T4 versus 275 MPa in T6.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASTM B209 — Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate — ASTM International (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Aluminum Alloys for Automotive Body Sheet (SAE technical literature) — SAE International (2015)
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.