Aluminum AL9-T2 vs AL9-T61
Aluminum · AL9 temper comparison
AL9-T2 and AL9-T61 are two conditions of the same aluminum grade, AL9: T2 (cooled from hot working, cold worked and naturally aged) versus T61 (T6 variant, underaged). The chemistry is identical, so every difference below comes from the condition. AL9-T61 is the stronger of the two: yield strength 215 MPa (31.2 ksi) against 85 MPa (12.3 ksi) for AL9-T2, about 153% more; tensile strength follows at 265 MPa (38.4 ksi) vs 150 MPa (21.8 ksi). In exchange, AL9-T2 is the more ductile: elongation 6% versus 3% for AL9-T61, and AL9-T61 is harder (90 HB vs 50 HB). AL9-T2 conducts electricity better (44 % IACS vs 39 % IACS). On the shop floor, AL9-T61 machines more easily (good vs fair) and AL9-T2 welds better (excellent vs very good).
AL9-T2Choose it when the part is bent, formed or impact-loaded, or when it will be welded.
AL9-T61Choose it when strength drives the design, or when the part is machined in volume.
AL9-T2 vs AL9-T61: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Shear Modulus 27 GPa3.9 Msi · Bulk Modulus 75 GPa10.9 Msi · Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Same in both: Density 2.68 g/cm³0.1 lb/in³ · Melting Point (Solidus) 557°C1,035 °F · Liquidus Temperature 613°C1,135 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 21.5 µm/m·K11.9 µin/in·°F · Latent Heat of Fusion 389 J/g167 BTU/lb · Max Service Temperature (continuous) 150°C302 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.83 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 92 / 100 · Brazeability / Solderability 35 / 100 · Polishability 50 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12 kg CO₂/kg · Embodied Water 1,200 L/kg144 gal/lb · Typical Recycled Content 60%
Strength versus weight
Yield strength against density for every aluminum grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
AL9-T2 vs AL9-T61 — frequently asked
Is AL9-T61 stronger than AL9-T2?
Yes. AL9-T61 has a typical yield strength of 215 MPa (31.2 ksi) against 85 MPa (12.3 ksi) for AL9-T2 — about 153% more. Tensile strength is 265 MPa (38.4 ksi) vs 150 MPa (21.8 ksi).
Which condition does FabDigit quote by default, T2 or T61?
T6 is the default AL9 condition in the FabDigit quote flow (neither T2 nor T61). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which is easier to machine, AL9-T2 or AL9-T61?
AL9-T61. Its machinability rates good (62/100) against fair (45/100) for AL9-T2; for welding the order is AL9-T2 first (excellent, 85/100) then AL9-T61 (very good, 75/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in AL9-T2 and AL9-T61 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.