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Aluminum AC8A-T6 vs AC8A-T7

Aluminum · AC8A temper comparison

AC8A-T6 and AC8A-T7 are two conditions of the same aluminum grade, AC8A: 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. AC8A-T6 is the stronger of the two: yield strength 240 MPa (34.8 ksi) against 195 MPa (28.3 ksi) for AC8A-T7, about 23% more; tensile strength follows at 285 MPa (41.3 ksi) vs 255 MPa (37 ksi). In exchange, AC8A-T7 is the more ductile: elongation 1.5% versus 1% for AC8A-T6, and AC8A-T6 is harder (115 HB vs 95 HB). AC8A-T7 runs hotter in service (280°C vs 250°C continuous).

AC8A-T6Choose it when strength drives the design.

AC8A-T7Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

AC8A-T6 vs AC8A-T7: properties

AC8A-T6AC8A-T7

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

82 GPa11.9 Msi
81 GPa11.7 Msi

Tensile Strength (Ultimate)

285 MPa41.3 ksi
255 MPa37 ksi

Yield Strength (0.2% offset)

240 MPa34.8 ksi
195 MPa28.3 ksi

Elongation at Break

1%
1.5%

Compressive Strength

340 MPa49.3 ksi
290 MPa42.1 ksi

Shear Strength

195 MPa28.3 ksi
180 MPa26.1 ksi

Fatigue Strength (Endurance Limit)

95 MPa13.8 ksi
85 MPa12.3 ksi

Fracture Toughness (K_IC)

16 MPa·√m14.6 ksi·√in
17 MPa·√m15.5 ksi·√in

Charpy V-Notch Impact (RT)

3 J1.8 ft·lbf
3 J2.2 ft·lbf

Hardness, Brinell

115 HB
95 HB

Hardness, Rockwell B

65 HRB
53 HRB

Hardness, Vickers

120 HV
100 HV

Same in both: Shear Modulus 27 GPa3.9 Msi · Bulk Modulus 76 GPa11 Msi · Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Same in both: Density 2.7 g/cm³0.1 lb/in³ · Melting Point (Solidus) 525°C977 °F · Liquidus Temperature 580°C1,076 °F

Thermal

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

Thermal Conductivity

130 W/m·K75.1 BTU/hr·ft·°F
140 W/m·K80.9 BTU/hr·ft·°F

Max Service Temperature (continuous)

250°C482 °F
280°C536 °F

Same in both: Specific Heat Capacity 880 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 19.5 µm/m·K10.8 µin/in·°F · Latent Heat of Fusion 470 J/g202 BTU/lb · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

28 % IACS
30 % IACS

Electrical Resistivity

6.2×10⁻⁸ Ω·m2.44 µΩ·in
5.75×10⁻⁸ Ω·m2.26 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

36 / 100
40 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.78 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

50 / 100
53 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
48%

Weldability

25 / 100
28 / 100

Formability (cold)

4 / 100
6 / 100

Same in both: Castability 85 / 100 · Brazeability / Solderability 20 / 100 · Polishability 45 / 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 kg CO₂/kg · Embodied Water 1,200 L/kg144 gal/lb · Typical Recycled Content 60%

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 scaleAC8A

AC8A-T6 vs AC8A-T7 — frequently asked

Is AC8A-T6 stronger than AC8A-T7?

Yes. AC8A-T6 has a typical yield strength of 240 MPa (34.8 ksi) against 195 MPa (28.3 ksi) for AC8A-T7 — about 23% more. Tensile strength is 285 MPa (41.3 ksi) vs 255 MPa (37 ksi).

Which condition does FabDigit quote by default, T6 or T7?

T6 is the default AC8A 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 AC8A-T6 over AC8A-T7?

Pick AC8A-T6 when strength drives the design. Pick AC8A-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 AC8A-T6 and AC8A-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.