Aluminum 356-T6 vs 356-T61
Aluminum · 356 temper comparison
356-T6 and 356-T61 are two conditions of the same aluminum grade, 356: T6 (solution heat treated and artificially aged) versus T61 (T6 variant, underaged). The chemistry is identical, so every difference below comes from the condition. 356-T61 is the stronger of the two: yield strength 207 MPa (30 ksi) against 186 MPa (27 ksi) for 356-T6, about 11% more; tensile strength follows at 283 MPa (41 ksi) vs 262 MPa (38 ksi). 356-T61 is the more ductile: elongation 10% versus 5% for 356-T6, and 356-T61 is harder (90 HB vs 80 HB).
356-T61Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
356-T6 vs 356-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
Compressive Strength
Shear Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 72.4 GPa10.5 Msi · Shear Modulus 27 GPa3.9 Msi · Bulk Modulus 71 GPa10.3 Msi · Poisson's Ratio 0.33 · Fatigue Strength (Endurance Limit) 90 MPa13.1 ksi
Physical
Density and transition temperatures.
Same in both: Density 2.67 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.
Same in both: Thermal Conductivity 151 W/m·K87.2 BTU/hr·ft·°F · 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.
Same in both: Electrical Conductivity 39 % IACS · Electrical Resistivity 4.4×10⁻⁸ Ω·m1.73 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.83 V · Corrosion Resistance 62 / 100
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 95 / 100 · Brazeability / Solderability 30 / 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 1,200 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.
356-T6 vs 356-T61 — frequently asked
Is 356-T61 stronger than 356-T6?
Yes. 356-T61 has a typical yield strength of 207 MPa (30 ksi) against 186 MPa (27 ksi) for 356-T6 — about 11% more. Tensile strength is 283 MPa (41 ksi) vs 262 MPa (38 ksi).
Which condition does FabDigit quote by default, T6 or T61?
Specify the condition in the material field or the drawing note; FabDigit prices the quote for the state you call out.
When should I choose 356-T6 over 356-T61?
Pick 356-T61 when strength drives the design, or when the part is bent, formed or impact-loaded.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 356-T6 and 356-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.