Aluminum AC1A-T4 vs AC1A-T6
Aluminum · AC1A temper comparison
AC1A-T4 and AC1A-T6 are two conditions of the same aluminum grade, AC1A: T4 (solution heat treated and naturally aged) versus T6 (solution heat treated and artificially aged). The chemistry is identical, so every difference below comes from the condition. AC1A-T6 is the stronger of the two: yield strength 250 MPa (36.3 ksi) against 180 MPa (26.1 ksi) for AC1A-T4, about 39% more; tensile strength follows at 335 MPa (48.6 ksi) vs 295 MPa (42.8 ksi). In exchange, AC1A-T4 is the more ductile: elongation 8% versus 4% for AC1A-T6, and AC1A-T6 is harder (95 HB vs 70 HB). AC1A-T6 runs hotter in service (175°C vs 150°C continuous) and AC1A-T6 conducts heat better (125 W/m·K vs 112 W/m·K).
AC1A-T4Choose it when the part is bent, formed or impact-loaded.
AC1A-T6Choose it when strength drives the design, or when the part sees heat.
AC1A-T4 vs AC1A-T6: 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)
Fracture Toughness (K_IC)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 71 GPa10.3 Msi · Shear Modulus 26.5 GPa3.8 Msi · Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.33 · Compressive Strength 255 MPa37 ksi
Physical
Density and transition temperatures.
Same in both: Density 2.8 g/cm³0.1 lb/in³ · Melting Point (Solidus) 545°C1,013 °F · Liquidus Temperature 645°C1,193 °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 920 J/kg·K0.22 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 22.5 µm/m·K12.5 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
Same in both: Electrical Resistivity 5.6×10⁻⁸ Ω·m2.2 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.7 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Same in both: Machinability Rating (AISI 1212 = 100 %) 190% · Weldability 25 / 100 · Castability 40 / 100 · Brazeability / Solderability 20 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 190 MJ/kg81,685 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg · Embodied Water 1,150 L/kg138 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.
AC1A-T4 vs AC1A-T6 — frequently asked
Is AC1A-T6 stronger than AC1A-T4?
Yes. AC1A-T6 has a typical yield strength of 250 MPa (36.3 ksi) against 180 MPa (26.1 ksi) for AC1A-T4 — about 39% more. Tensile strength is 335 MPa (48.6 ksi) vs 295 MPa (42.8 ksi).
Which condition does FabDigit quote by default, T4 or T6?
T6 is the default AC1A condition in the FabDigit quote flow. 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 AC1A-T4 over AC1A-T6?
Pick AC1A-T4 when the part is bent, formed or impact-loaded. Pick AC1A-T6 when strength drives the design, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AC1A-T4 and AC1A-T6 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.