Aluminum AC9B-T6 vs AC9B-T7
Aluminum · AC9B temper comparison
AC9B-T6 and AC9B-T7 are two conditions of the same aluminum grade, AC9B: 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. AC9B-T6 is the stronger of the two: yield strength 200 MPa (29 ksi) against 165 MPa (23.9 ksi) for AC9B-T7, about 21% more; tensile strength follows at 220 MPa (31.9 ksi) vs 185 MPa (26.8 ksi). In exchange, AC9B-T7 is the more ductile: elongation 0.8% versus 0.5% for AC9B-T6, and AC9B-T6 is harder (140 HB vs 110 HB). AC9B-T7 runs hotter in service (280°C vs 250°C continuous).
AC9B-T6Choose it when strength drives the design.
AC9B-T7Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
AC9B-T6 vs AC9B-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
Same in both: Elastic (Young's) Modulus 82 GPa11.9 Msi · Shear Modulus 31 GPa4.5 Msi · Bulk Modulus 76 GPa11 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) 507°C945 °F · Liquidus Temperature 670°C1,238 °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 880 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 17.8 µm/m·K9.9 µin/in·°F · Latent Heat of Fusion 425 J/g183 BTU/lb · Min Service Temperature -80°C-112 °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) -0.8 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 70 / 100 · Brazeability / Solderability 20 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 155 MJ/kg66,638 BTU/lb · Embodied Carbon (primary production) 10.5 kg CO₂/kg · Embodied Water 1,100 L/kg132 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.
AC9B-T6 vs AC9B-T7 — frequently asked
Is AC9B-T6 stronger than AC9B-T7?
Yes. AC9B-T6 has a typical yield strength of 200 MPa (29 ksi) against 165 MPa (23.9 ksi) for AC9B-T7 — about 21% more. Tensile strength is 220 MPa (31.9 ksi) vs 185 MPa (26.8 ksi).
Which condition does FabDigit quote by default, T6 or T7?
T6 is the default AC9B 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 AC9B-T6 over AC9B-T7?
Pick AC9B-T6 when strength drives the design. Pick AC9B-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 AC9B-T6 and AC9B-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.