Aluminum 2025-O vs 2025-T4
Aluminum · 2025 temper comparison
2025-O and 2025-T4 are two conditions of the same aluminum grade, 2025: O (annealed) versus T4 (solution heat treated and naturally aged). The chemistry is identical, so every difference below comes from the condition. 2025-T4 is the stronger of the two: yield strength 215 MPa (31.2 ksi) against 95 MPa (13.8 ksi) for 2025-O, about 126% more; tensile strength follows at 370 MPa (53.7 ksi) vs 205 MPa (29.7 ksi). 2025-T4 is harder — 100 HB against 55 HB for 2025-O — which matters for wear surfaces and threads. 2025-O runs hotter in service (150°C vs 120°C continuous) and 2025-O conducts heat better (180 W/m·K vs 134 W/m·K). On the shop floor, 2025-T4 machines more easily (good vs fair) and 2025-O forms better (very good vs fair).
2025-OChoose it when the part sees heat.
2025-T4Choose it when strength drives the design, or when surface hardness matters.
2025-O vs 2025-T4: 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
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 72 GPa10.4 Msi · 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 2.81 g/cm³0.1 lb/in³ · Melting Point (Solidus) 520°C968 °F · Liquidus Temperature 640°C1,184 °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) 22.7 µm/m·K12.6 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
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.64 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 25 / 100 · Brazeability / Solderability 20 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 205 MJ/kg88,134 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.
2025-O vs 2025-T4 — frequently asked
Is 2025-T4 stronger than 2025-O?
Yes. 2025-T4 has a typical yield strength of 215 MPa (31.2 ksi) against 95 MPa (13.8 ksi) for 2025-O — about 126% more. Tensile strength is 370 MPa (53.7 ksi) vs 205 MPa (29.7 ksi).
Which condition does FabDigit quote by default, O or T4?
T6 is the default 2025 condition in the FabDigit quote flow (neither O nor T4). 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, 2025-O or 2025-T4?
2025-T4. Its machinability rates good (60/100) against fair (40/100) for 2025-O.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 2025-O and 2025-T4 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.