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Aluminum AL4-T5 vs AL4-T6

Aluminum · AL4 temper comparison

AL4-T5 and AL4-T6 are two conditions of the same aluminum grade, AL4: 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. AL4-T6 is the stronger of the two: yield strength 180 MPa (26.1 ksi) against 140 MPa (20.3 ksi) for AL4-T5, about 29% more; tensile strength follows at 240 MPa (34.8 ksi) vs 180 MPa (26.1 ksi). AL4-T6 is the more ductile: elongation 4% versus 2% for AL4-T5, and AL4-T6 is harder (75 HB vs 60 HB).

AL4-T6Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

AL4-T5 vs AL4-T6: properties

AL4-T5AL4-T6

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

180 MPa26.1 ksi
240 MPa34.8 ksi

Yield Strength (0.2% offset)

140 MPa20.3 ksi
180 MPa26.1 ksi

Elongation at Break

2%
4%

Compressive Strength

145 MPa21 ksi
185 MPa26.8 ksi

Shear Strength

130 MPa18.9 ksi
180 MPa26.1 ksi

Fatigue Strength (Endurance Limit)

70 MPa10.2 ksi
90 MPa13.1 ksi

Fracture Toughness (K_IC)

19 MPa·√m17.3 ksi·√in
20 MPa·√m18.2 ksi·√in

Charpy V-Notch Impact (RT)

3 J2.2 ft·lbf
5 J3.7 ft·lbf

Hardness, Brinell

60 HB
75 HB

Same in both: Elastic (Young's) Modulus 72.4 GPa10.5 Msi · Shear Modulus 27 GPa3.9 Msi · Bulk Modulus 71 GPa10.3 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 613°C1,135 °F

Thermal

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

Thermal Conductivity

165 W/m·K95.3 BTU/hr·ft·°F
151 W/m·K87.2 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 -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

43 % IACS
39 % IACS

Electrical Resistivity

4×10⁻⁸ Ω·m1.57 µΩ·in
4.4×10⁻⁸ Ω·m1.73 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

63 / 100
62 / 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

52 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
60%

Weldability

78 / 100
80 / 100

Formability (cold)

11 / 100
12 / 100

Same in both: Castability 92 / 100 · Brazeability / Solderability 35 / 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 1,150 L/kg138 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.

20501002005002.22.42.62.83Density (g/cm³)Yield strength (MPa) — log scaleAL4

AL4-T5 vs AL4-T6 — frequently asked

Is AL4-T6 stronger than AL4-T5?

Yes. AL4-T6 has a typical yield strength of 180 MPa (26.1 ksi) against 140 MPa (20.3 ksi) for AL4-T5 — about 29% more. Tensile strength is 240 MPa (34.8 ksi) vs 180 MPa (26.1 ksi).

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

T6 is the default AL4 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, AL4-T5 or AL4-T6?

AL4-T6. Its machinability rates good (58/100) against fair (52/100) for AL4-T5.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AL4-T5 and AL4-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.