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Aluminum 2A12-O vs 2A12-T3

Aluminum · 2A12 temper comparison

2A12-O and 2A12-T3 are two conditions of the same aluminum grade, 2A12: O (annealed) versus T3 (solution heat treated, cold worked and naturally aged). The chemistry is identical, so every difference below comes from the condition. 2A12-T3 is the stronger of the two: yield strength 345 MPa (50 ksi) against 75 MPa (10.9 ksi) for 2A12-O, about 4.6 times as much; tensile strength follows at 485 MPa (70.3 ksi) vs 185 MPa (26.8 ksi). In exchange, 2A12-O is the more ductile: elongation 20% versus 18% for 2A12-T3, and 2A12-T3 is harder (120 HB vs 47 HB). 2A12-O runs hotter in service (150°C vs 120°C continuous) and 2A12-O conducts heat better (193 W/m·K vs 121 W/m·K). On the shop floor, 2A12-T3 machines more easily (very good vs fair).

2A12-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

2A12-T3Choose it when strength drives the design, or when the part is machined in volume.

2A12-O vs 2A12-T3: properties

2A12-O2A12-T3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

185 MPa26.8 ksi
485 MPa70.3 ksi

Yield Strength (0.2% offset)

75 MPa10.9 ksi
345 MPa50 ksi

Elongation at Break

20%
18%

Shear Strength

125 MPa18.1 ksi
285 MPa41.3 ksi

Fatigue Strength (Endurance Limit)

90 MPa13.1 ksi
138 MPa20 ksi

Fracture Toughness (K_IC)

37 MPa·√m33.7 ksi·√in
40 MPa·√m36.4 ksi·√in

Hardness, Brinell

47 HB
120 HB

Hardness, Rockwell B

23 HRB
75 HRB

Same in both: Elastic (Young's) Modulus 73 GPa10.6 Msi · Shear Modulus 28 GPa4.1 Msi · Bulk Modulus 75 GPa10.9 Msi · Poisson's Ratio 0.33 · Reduction in Area 25% · Compressive Strength 325 MPa47.1 ksi · Hardness, Vickers 128 HV

Physical

Density and transition temperatures.

Same in both: Density 2.78 g/cm³0.1 lb/in³ · Melting Point (Solidus) 502°C936 °F · Liquidus Temperature 638°C1,180 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

193 W/m·K112 BTU/hr·ft·°F
121 W/m·K69.9 BTU/hr·ft·°F

Max Service Temperature (continuous)

150°C302 °F
120°C248 °F

Same in both: Specific Heat Capacity 875 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 23.2 µm/m·K12.9 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

50 % IACS
30 % IACS

Electrical Resistivity

3.45×10⁻⁸ Ω·m1.36 µΩ·in
5.75×10⁻⁸ Ω·m2.26 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

40 / 100
30 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.69 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

45 / 100
72 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
70%

Formability (cold)

80 / 100
40 / 100

Same in both: Weldability 15 / 100 · Castability 20 / 100 · Brazeability / Solderability 15 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 210 MJ/kg90,284 BTU/lb · Embodied Carbon (primary production) 13.5 kg CO₂/kg · Embodied Water 1,200 L/kg144 gal/lb · Typical Recycled Content 15%

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.

20501002005002.22.42.62.83Density (g/cm³)Yield strength (MPa) — log scale2A12

2A12-O vs 2A12-T3 — frequently asked

Is 2A12-T3 stronger than 2A12-O?

Yes. 2A12-T3 has a typical yield strength of 345 MPa (50 ksi) against 75 MPa (10.9 ksi) for 2A12-O — about 4.6 times as much. Tensile strength is 485 MPa (70.3 ksi) vs 185 MPa (26.8 ksi).

Which condition does FabDigit quote by default, O or T3?

T4 is the default 2A12 condition in the FabDigit quote flow (neither O nor T3). 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, 2A12-O or 2A12-T3?

2A12-T3. Its machinability rates very good (72/100) against fair (45/100) for 2A12-O.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 2A12-O and 2A12-T3 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.