Aluminum AC4CH-T4 vs AC4CH-T61
Aluminum · AC4CH temper comparison
AC4CH-T4 and AC4CH-T61 are two conditions of the same aluminum grade, AC4CH: T4 (solution heat treated and naturally aged) versus T61 (T6 variant, underaged). The chemistry is identical, so every difference below comes from the condition. AC4CH-T61 is the stronger of the two: yield strength 240 MPa (34.8 ksi) against 120 MPa (17.4 ksi) for AC4CH-T4, about 100% more; tensile strength follows at 300 MPa (43.5 ksi) vs 230 MPa (33.4 ksi). In exchange, AC4CH-T4 is the more ductile: elongation 12% versus 5% for AC4CH-T61, and AC4CH-T61 is harder (95 HB vs 60 HB). AC4CH-T61 runs hotter in service (150°C vs 120°C continuous).
AC4CH-T4Choose it when the part is bent, formed or impact-loaded.
AC4CH-T61Choose it when strength drives the design, or when the part sees heat.
AC4CH-T4 vs AC4CH-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
Fatigue Strength (Endurance Limit)
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
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
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 75 / 100 · Castability 92 / 100 · Brazeability / Solderability 30 / 100 · Polishability 55 / 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 1,100 L/kg132 gal/lb · Typical Recycled Content 20%
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.
AC4CH-T4 vs AC4CH-T61 — frequently asked
Is AC4CH-T61 stronger than AC4CH-T4?
Yes. AC4CH-T61 has a typical yield strength of 240 MPa (34.8 ksi) against 120 MPa (17.4 ksi) for AC4CH-T4 — about 100% more. Tensile strength is 300 MPa (43.5 ksi) vs 230 MPa (33.4 ksi).
Which condition does FabDigit quote by default, T4 or T61?
T6 is the default AC4CH condition in the FabDigit quote flow (neither T4 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, AC4CH-T4 or AC4CH-T61?
AC4CH-T61, by a small margin. Both rate good for machinability — 62/100 against 55/100 for AC4CH-T4.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AC4CH-T4 and AC4CH-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.