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Aluminum AC4B-F vs AC4B-T6

Aluminum · AC4B temper comparison

AC4B-F and AC4B-T6 are two conditions of the same aluminum grade, AC4B: F (as fabricated) versus T6 (solution heat treated and artificially aged). 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 110 MPa (16 ksi) for AC4B-F, about 68% more; tensile strength follows at 275 MPa (39.9 ksi) vs 180 MPa (26.1 ksi). AC4B-T6 is harder — 92 HB against 75 HB for AC4B-F — which matters for wear surfaces and threads.

AC4B-T6Choose it when strength drives the design, or when surface hardness matters.

AC4B-F vs AC4B-T6: properties

AC4B-FAC4B-T6

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

180 MPa26.1 ksi
275 MPa39.9 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
185 MPa26.8 ksi

Shear Strength

150 MPa21.8 ksi
210 MPa30.5 ksi

Fatigue Strength (Endurance Limit)

70 MPa10.2 ksi
75 MPa10.9 ksi

Fracture Toughness (K_IC)

18 MPa·√m16.4 ksi·√in
17 MPa·√m15.5 ksi·√in

Hardness, Brinell

75 HB
92 HB

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 · Elongation at Break 2% · Charpy V-Notch Impact (RT) 3 J2.2 ft·lbf

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

109 W/m·K63 BTU/hr·ft·°F
104 W/m·K60.1 BTU/hr·ft·°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 389 J/g167 BTU/lb · Max Service Temperature (continuous) 150°C302 °F · Min Service Temperature -195°C-319 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

27 % IACS
25 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
6.9×10⁻⁸ Ω·m2.72 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

40 / 100
38 / 100

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

68 / 100
75 / 100

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.

20501002005002.22.42.62.83Density (g/cm³)Yield strength (MPa) — log scaleAC4B

AC4B-F vs AC4B-T6 — frequently asked

Is AC4B-T6 stronger than AC4B-F?

Yes. AC4B-T6 has a typical yield strength of 185 MPa (26.8 ksi) against 110 MPa (16 ksi) for AC4B-F — about 68% more. Tensile strength is 275 MPa (39.9 ksi) vs 180 MPa (26.1 ksi).

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

F is the default AC4B 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.

Which is easier to machine, AC4B-F or AC4B-T6?

AC4B-T6. Its machinability rates very good (75/100) against good (68/100) for AC4B-F.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC4B-F and AC4B-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.