Aluminum AC4B-T6 vs AC4B-T7
Aluminum · AC4B temper comparison
AC4B-T6 and AC4B-T7 are two conditions of the same aluminum grade, AC4B: T6 (solution heat treated and artificially aged) versus T7 (solution heat treated and overaged (stabilized)). The chemistry is identical, so every difference below comes from the condition. AC4B-T6 is the stronger of the two: yield strength 185 MPa (26.8 ksi) against 170 MPa (24.7 ksi) for AC4B-T7, about 9% more; tensile strength follows at 275 MPa (39.9 ksi) vs 240 MPa (34.8 ksi). In exchange, AC4B-T7 is the more ductile: elongation 2.5% versus 2% for AC4B-T6, and AC4B-T6 is harder (92 HB vs 85 HB). AC4B-T7 runs hotter in service (200°C vs 150°C continuous) and AC4B-T7 conducts electricity better (29 % IACS vs 25 % IACS).
AC4B-T6Choose it when strength drives the design.
AC4B-T7Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
AC4B-T6 vs AC4B-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
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 74 GPa10.7 Msi · Shear Modulus 27.5 GPa4 Msi · Bulk Modulus 72 GPa10.4 Msi · Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Same in both: Density 2.79 g/cm³0.1 lb/in³ · Melting Point (Solidus) 516°C961 °F · Liquidus Temperature 604°C1,119 °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 -195°C-319 °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) -0.81 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Same in both: Weldability 45 / 100 · Castability 85 / 100 · Brazeability / Solderability 25 / 100 · Polishability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 150 MJ/kg64,488 BTU/lb · Embodied Carbon (primary production) 11.5 kg CO₂/kg · Embodied Water 1,200 L/kg144 gal/lb · Typical Recycled Content 85%
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.
AC4B-T6 vs AC4B-T7 — frequently asked
Is AC4B-T6 stronger than AC4B-T7?
Yes. AC4B-T6 has a typical yield strength of 185 MPa (26.8 ksi) against 170 MPa (24.7 ksi) for AC4B-T7 — about 9% more. Tensile strength is 275 MPa (39.9 ksi) vs 240 MPa (34.8 ksi).
Which condition does FabDigit quote by default, T6 or T7?
F is the default AC4B condition in the FabDigit quote flow (neither T6 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 AC4B-T6 over AC4B-T7?
Pick AC4B-T6 when strength drives the design. Pick AC4B-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 AC4B-T6 and AC4B-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.