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Aluminum AC9A-T5 vs AC9A-T6

Aluminum · AC9A temper comparison

AC9A-T5 and AC9A-T6 are two conditions of the same aluminum grade, AC9A: T5 (cooled from hot working and artificially aged) versus T6 (solution heat treated and artificially aged). The chemistry is identical, so every difference below comes from the condition. AC9A-T6 is the stronger of the two: yield strength 190 MPa (27.6 ksi) against 170 MPa (24.7 ksi) for AC9A-T5, about 12% more; tensile strength follows at 210 MPa (30.5 ksi) vs 190 MPa (27.6 ksi). AC9A-T6 is harder — 135 HB against 105 HB for AC9A-T5 — which matters for wear surfaces and threads.

AC9A-T6Choose it when strength drives the design, or when surface hardness matters.

AC9A-T5 vs AC9A-T6: properties

AC9A-T5AC9A-T6

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

190 MPa27.6 ksi
210 MPa30.5 ksi

Yield Strength (0.2% offset)

170 MPa24.7 ksi
190 MPa27.6 ksi

Reduction in Area

0.8%
0.5%

Compressive Strength

430 MPa62.4 ksi
480 MPa69.6 ksi

Shear Strength

148 MPa21.5 ksi
160 MPa23.2 ksi

Fatigue Strength (Endurance Limit)

82 MPa11.9 ksi
90 MPa13.1 ksi

Fracture Toughness (K_IC)

11.5 MPa·√m10.5 ksi·√in
11 MPa·√m10 ksi·√in

Charpy V-Notch Impact (RT)

1 J0.89 ft·lbf
1 J0.74 ft·lbf

Hardness, Brinell

105 HB
135 HB

Hardness, Rockwell B

60 HRB
75 HRB

Hardness, Vickers

111 HV
142 HV

Same in both: Elastic (Young's) Modulus 88 GPa12.8 Msi · Shear Modulus 34 GPa4.9 Msi · Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.32 · Elongation at Break 0.4%

Physical

Density and transition temperatures.

Same in both: Density 2.66 g/cm³0.1 lb/in³ · Melting Point (Solidus) 510°C950 °F · Liquidus Temperature 700°C1,292 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

125 W/m·K72.2 BTU/hr·ft·°F
120 W/m·K69.3 BTU/hr·ft·°F

Max Service Temperature (continuous)

240°C464 °F
250°C482 °F

Same in both: Specific Heat Capacity 870 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 17 µm/m·K9.4 µin/in·°F · Latent Heat of Fusion 440 J/g189 BTU/lb · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

26 % IACS
24 % IACS

Electrical Resistivity

6.6×10⁻⁸ Ω·m2.6 µΩ·in
7.2×10⁻⁸ Ω·m2.83 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

45 / 100
44 / 100

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

26 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

31%
30%

Weldability

21 / 100
20 / 100

Same in both: Formability (cold) 5 / 100 · Castability 65 / 100 · Brazeability / Solderability 25 / 100 · Polishability 40 / 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 35%

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.

20501002005002.22.42.62.83Density (g/cm³)Yield strength (MPa) — log scaleAC9A

AC9A-T5 vs AC9A-T6 — frequently asked

Is AC9A-T6 stronger than AC9A-T5?

Yes. AC9A-T6 has a typical yield strength of 190 MPa (27.6 ksi) against 170 MPa (24.7 ksi) for AC9A-T5 — about 12% more. Tensile strength is 210 MPa (30.5 ksi) vs 190 MPa (27.6 ksi).

Which condition does FabDigit quote by default, T5 or T6?

T6 is the default AC9A 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 AC9A-T5 over AC9A-T6?

Pick AC9A-T6 when strength drives the design, or when surface hardness matters.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC9A-T5 and AC9A-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.