Aluminum A242.0-O vs A242.0-T61
Aluminum · A242.0 temper comparison
A242.0-O and A242.0-T61 are two conditions of the same aluminum grade, A242.0: O (annealed) versus T61 (T6 variant, underaged). The chemistry is identical, so every difference below comes from the condition. A242.0-T61 is the stronger of the two: yield strength 234 MPa (33.9 ksi) against 124 MPa (18 ksi) for A242.0-O, about 89% more; tensile strength follows at 276 MPa (40 ksi) vs 186 MPa (27 ksi). In exchange, A242.0-O is the more ductile: elongation 1% versus 0.5% for A242.0-T61, and A242.0-T61 is harder (105 HB vs 70 HB). A242.0-O runs hotter in service (300°C vs 230°C continuous) and A242.0-O conducts heat better (155 W/m·K vs 130 W/m·K). On the shop floor, A242.0-T61 machines more easily (good vs fair).
A242.0-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
A242.0-T61Choose it when strength drives the design, or when the part is machined in volume.
A242.0-O vs A242.0-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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 71 GPa10.3 Msi · Shear Modulus 27 GPa3.9 Msi · Bulk Modulus 72 GPa10.4 Msi · Poisson's Ratio 0.33 · Fracture Toughness (K_IC) 20 MPa·√m18.2 ksi·√in
Physical
Density and transition temperatures.
Same in both: Density 2.81 g/cm³0.1 lb/in³ · Melting Point (Solidus) 528°C982 °F · Liquidus Temperature 635°C1,175 °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 963 J/kg·K0.23 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 22.5 µm/m·K12.5 µin/in·°F · Latent Heat of Fusion 389 J/g167 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Same in both: Electrical Resistivity 4.8×10⁻⁸ Ω·m1.89 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.75 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Same in both: Machinability Rating (AISI 1212 = 100 %) 190% · Weldability 22 / 100 · Castability 42 / 100 · Brazeability / Solderability 15 / 100 · Polishability 45 / 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 25%
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.
A242.0-O vs A242.0-T61 — frequently asked
Is A242.0-T61 stronger than A242.0-O?
Yes. A242.0-T61 has a typical yield strength of 234 MPa (33.9 ksi) against 124 MPa (18 ksi) for A242.0-O — about 89% more. Tensile strength is 276 MPa (40 ksi) vs 186 MPa (27 ksi).
Which condition does FabDigit quote by default, O or T61?
T75 is the default A242.0 condition in the FabDigit quote flow (neither O 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, A242.0-O or A242.0-T61?
A242.0-T61. Its machinability rates good (68/100) against fair (52/100) for A242.0-O.
Ready to make it?
Upload a CAD file and FabDigit prices the part in A242.0-O and A242.0-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.