Aluminum AC4C-T61 vs AC4C-T7
Aluminum · AC4C temper comparison
AC4C-T61 and AC4C-T7 are two conditions of the same aluminum grade, AC4C: T61 (T6 variant, underaged) versus T7 (solution heat treated and overaged (stabilized)). The chemistry is identical, so every difference below comes from the condition. AC4C-T61 is the stronger of the two: yield strength 225 MPa (32.6 ksi) against 195 MPa (28.3 ksi) for AC4C-T7, about 15% more; tensile strength follows at 280 MPa (40.6 ksi) vs 230 MPa (33.4 ksi). In exchange, AC4C-T7 is the more ductile: elongation 5% versus 3% for AC4C-T61, and AC4C-T61 is harder (90 HB vs 70 HB). AC4C-T7 runs hotter in service (200°C vs 150°C continuous).
AC4C-T61Choose it when strength drives the design.
AC4C-T7Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
AC4C-T61 vs AC4C-T7: 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
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
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
Physical
Density and transition temperatures.
Same in both: Density 2.68 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.
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) 21.5 µm/m·K11.9 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
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.83 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Same in both: Castability 93 / 100 · Brazeability / Solderability 30 / 100 · Polishability 50 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 175 MJ/kg75,237 BTU/lb · Embodied Carbon (primary production) 11.5 kg CO₂/kg · Embodied Water 1,200 L/kg144 gal/lb · Typical Recycled Content 55%
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.
AC4C-T61 vs AC4C-T7 — frequently asked
Is AC4C-T61 stronger than AC4C-T7?
Yes. AC4C-T61 has a typical yield strength of 225 MPa (32.6 ksi) against 195 MPa (28.3 ksi) for AC4C-T7 — about 15% more. Tensile strength is 280 MPa (40.6 ksi) vs 230 MPa (33.4 ksi).
Which condition does FabDigit quote by default, T61 or T7?
T6 is the default AC4C condition in the FabDigit quote flow (neither T61 nor T7). 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.
When should I choose AC4C-T61 over AC4C-T7?
Pick AC4C-T61 when strength drives the design. Pick AC4C-T7 when the part is bent, formed or impact-loaded, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AC4C-T61 and AC4C-T7 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.