Aluminum 2A70-O vs 2A70-T6
Aluminum · 2A70 temper comparison
2A70-O and 2A70-T6 are two conditions of the same aluminum grade, 2A70: O (annealed) versus T6 (solution heat treated and artificially aged). The chemistry is identical, so every difference below comes from the condition. 2A70-T6 is the stronger of the two: yield strength 350 MPa (50.8 ksi) against 120 MPa (17.4 ksi) for 2A70-O, about 192% more; tensile strength follows at 430 MPa (62.4 ksi) vs 230 MPa (33.4 ksi). In exchange, 2A70-O is the more ductile: elongation 18% versus 10% for 2A70-T6, and 2A70-T6 is harder (120 HB vs 65 HB). 2A70-T6 runs hotter in service (200°C vs 150°C continuous) and 2A70-O conducts heat better (175 W/m·K vs 145 W/m·K). On the shop floor, 2A70-T6 machines more easily (very good vs fair).
2A70-OChoose it when the part is bent, formed or impact-loaded.
2A70-T6Choose it when strength drives the design, or when the part sees heat.
2A70-O vs 2A70-T6: 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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 73 GPa10.6 Msi · Shear Modulus 27.5 GPa4 Msi · Bulk Modulus 71 GPa10.3 Msi · Poisson's Ratio 0.33 · Reduction in Area 22% · Compressive Strength 355 MPa51.5 ksi · Fatigue Strength (Endurance Limit) 125 MPa18.1 ksi · Fracture Toughness (K_IC) 27 MPa·√m24.6 ksi·√in · Charpy V-Notch Impact (RT) 12 J8.9 ft·lbf · Hardness, Vickers 130 HV
Physical
Density and transition temperatures.
Same in both: Density 2.8 g/cm³0.1 lb/in³ · Melting Point (Solidus) 505°C941 °F · Liquidus Temperature 638°C1,180 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 875 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 22.3 µm/m·K12.4 µin/in·°F · Latent Heat of Fusion 390 J/g168 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Same in both: Electrical Resistivity 4.5×10⁻⁸ Ω·m1.77 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.68 V · Corrosion Resistance 32 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Formability (cold)
Same in both: Machinability Rating (AISI 1212 = 100 %) 60% · Weldability 22 / 100 · Castability 35 / 100 · Brazeability / Solderability 15 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg · Embodied Water 1,150 L/kg138 gal/lb · Typical Recycled Content 10%
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.
2A70-O vs 2A70-T6 — frequently asked
Is 2A70-T6 stronger than 2A70-O?
Yes. 2A70-T6 has a typical yield strength of 350 MPa (50.8 ksi) against 120 MPa (17.4 ksi) for 2A70-O — about 192% more. Tensile strength is 430 MPa (62.4 ksi) vs 230 MPa (33.4 ksi).
Which condition does FabDigit quote by default, O or T6?
T6 is the default 2A70 condition in the FabDigit quote flow. 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, 2A70-O or 2A70-T6?
2A70-T6. Its machinability rates very good (72/100) against fair (50/100) for 2A70-O.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 2A70-O and 2A70-T6 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.