Aluminum AC4C-T5 vs AC4C-T61
Aluminum · AC4C temper comparison
AC4C-T5 and AC4C-T61 are two conditions of the same aluminum grade, AC4C: T5 (cooled from hot working and artificially aged) versus T61 (T6 variant, underaged). 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 125 MPa (18.1 ksi) for AC4C-T5, about 80% more; tensile strength follows at 280 MPa (40.6 ksi) vs 185 MPa (26.8 ksi). In exchange, AC4C-T5 is the more ductile: elongation 4% versus 3% for AC4C-T61, and AC4C-T61 is harder (90 HB vs 65 HB). AC4C-T5 runs hotter in service (175°C vs 150°C continuous).
AC4C-T5Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
AC4C-T61Choose it when strength drives the design.
AC4C-T5 vs AC4C-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 72.4 GPa10.5 Msi · Shear Modulus 27 GPa3.9 Msi · Bulk Modulus 71 GPa10.3 Msi · Poisson's Ratio 0.33 · Compressive Strength 185 MPa26.8 ksi · Fracture Toughness (K_IC) 20 MPa·√m18.2 ksi·√in · Charpy V-Notch Impact (RT) 5 J3.7 ft·lbf · Hardness, Vickers 85 HV
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
Same in both: 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 58 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Same in both: Weldability 75 / 100 · Formability (cold) 12 / 100 · 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-T5 vs AC4C-T61 — frequently asked
Is AC4C-T61 stronger than AC4C-T5?
Yes. AC4C-T61 has a typical yield strength of 225 MPa (32.6 ksi) against 125 MPa (18.1 ksi) for AC4C-T5 — about 80% more. Tensile strength is 280 MPa (40.6 ksi) vs 185 MPa (26.8 ksi).
Which condition does FabDigit quote by default, T5 or T61?
T6 is the default AC4C condition in the FabDigit quote flow (neither T5 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, AC4C-T5 or AC4C-T61?
AC4C-T61, by a small margin. Both rate good for machinability — 64/100 against 58/100 for AC4C-T5.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AC4C-T5 and AC4C-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.