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Aluminum AC4A-F vs AC4A-T4

Aluminum · AC4A temper comparison

AC4A-F and AC4A-T4 are two conditions of the same aluminum grade, AC4A: F (as fabricated) versus T4 (solution heat treated and naturally aged). The chemistry is identical, so every difference below comes from the condition. AC4A-T4 is the stronger of the two: yield strength 115 MPa (16.7 ksi) against 90 MPa (13.1 ksi) for AC4A-F, about 28% more; tensile strength follows at 215 MPa (31.2 ksi) vs 170 MPa (24.7 ksi). AC4A-T4 is the more ductile: elongation 8% versus 4% for AC4A-F, and AC4A-T4 is harder (65 HB vs 58 HB). AC4A-F runs hotter in service (175°C vs 100°C continuous) and AC4A-F conducts electricity better (40 % IACS vs 36 % IACS).

AC4A-FChoose it when the part sees heat.

AC4A-T4Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

AC4A-F vs AC4A-T4: properties

AC4A-FAC4A-T4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

170 MPa24.7 ksi
215 MPa31.2 ksi

Yield Strength (0.2% offset)

90 MPa13.1 ksi
115 MPa16.7 ksi

Elongation at Break

4%
8%

Compressive Strength

205 MPa29.7 ksi
120 MPa17.4 ksi

Shear Strength

130 MPa18.9 ksi
150 MPa21.8 ksi

Fatigue Strength (Endurance Limit)

60 MPa8.7 ksi
70 MPa10.2 ksi

Fracture Toughness (K_IC)

18 MPa·√m16.4 ksi·√in
22 MPa·√m20 ksi·√in

Charpy V-Notch Impact (RT)

4 J3 ft·lbf
8 J5.9 ft·lbf

Hardness, Brinell

58 HB
65 HB

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

Physical

Density and transition temperatures.

Same in both: Density 2.68 g/cm³0.1 lb/in³ · Melting Point (Solidus) 557°C1,035 °F · Liquidus Temperature 596°C1,105 °F

Thermal

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

Thermal Conductivity

155 W/m·K89.6 BTU/hr·ft·°F
145 W/m·K83.8 BTU/hr·ft·°F

Max Service Temperature (continuous)

175°C347 °F
100°C212 °F

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 425 J/g183 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

40 % IACS
36 % IACS

Electrical Resistivity

4.4×10⁻⁸ Ω·m1.73 µΩ·in
4.8×10⁻⁸ Ω·m1.89 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

58 / 100
60 / 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

55 / 100
48 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Weldability

65 / 100
68 / 100

Formability (cold)

10 / 100
14 / 100

Same in both: Castability 88 / 100 · Brazeability / Solderability 25 / 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) 9.5 kg CO₂/kg · Embodied Water 1,100 L/kg132 gal/lb · Typical Recycled Content 70%

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 scaleAC4A

AC4A-F vs AC4A-T4 — frequently asked

Is AC4A-T4 stronger than AC4A-F?

Yes. AC4A-T4 has a typical yield strength of 115 MPa (16.7 ksi) against 90 MPa (13.1 ksi) for AC4A-F — about 28% more. Tensile strength is 215 MPa (31.2 ksi) vs 170 MPa (24.7 ksi).

Which condition does FabDigit quote by default, F or T4?

T6 is the default AC4A condition in the FabDigit quote flow (neither F nor T4). 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.

Which is easier to machine, AC4A-F or AC4A-T4?

AC4A-F. Its machinability rates good (55/100) against fair (48/100) for AC4A-T4.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC4A-F and AC4A-T4 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.