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Aluminum EN AC-21000-T4 vs EN AC-21000-T6

Aluminum · EN AC-21000 temper comparison

EN AC-21000-T4 and EN AC-21000-T6 are two conditions of the same aluminum grade, EN AC-21000: T4 (solution heat treated and naturally aged) versus T6 (solution heat treated and artificially aged). The chemistry is identical, so every difference below comes from the condition. EN AC-21000-T6 is the stronger of the two: yield strength 320 MPa (46.4 ksi) against 210 MPa (30.5 ksi) for EN AC-21000-T4, about 52% more; tensile strength follows at 390 MPa (56.6 ksi) vs 320 MPa (46.4 ksi). In exchange, EN AC-21000-T4 is the more ductile: elongation 7% versus 3% for EN AC-21000-T6, and EN AC-21000-T6 is harder (115 HB vs 92 HB). EN AC-21000-T6 runs hotter in service (175°C vs 150°C continuous).

EN AC-21000-T4Choose it when the part is bent, formed or impact-loaded.

EN AC-21000-T6Choose it when strength drives the design, or when the part sees heat.

EN AC-21000-T4 vs EN AC-21000-T6: properties

EN AC-21000-T4EN AC-21000-T6

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

320 MPa46.4 ksi
390 MPa56.6 ksi

Yield Strength (0.2% offset)

210 MPa30.5 ksi
320 MPa46.4 ksi

Elongation at Break

7%
3%

Compressive Strength

215 MPa31.2 ksi
330 MPa47.9 ksi

Shear Strength

200 MPa29 ksi
240 MPa34.8 ksi

Fatigue Strength (Endurance Limit)

95 MPa13.8 ksi
105 MPa15.2 ksi

Fracture Toughness (K_IC)

32 MPa·√m29.1 ksi·√in
24 MPa·√m21.8 ksi·√in

Hardness, Brinell

92 HB
115 HB

Same in both: Elastic (Young's) Modulus 71 GPa10.3 Msi · Shear Modulus 26.5 GPa3.8 Msi · Bulk Modulus 75 GPa10.9 Msi · Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Same in both: Density 2.8 g/cm³0.1 lb/in³ · Melting Point (Solidus) 548°C1,018 °F · Liquidus Temperature 650°C1,202 °F

Thermal

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

Thermal Conductivity

112 W/m·K64.7 BTU/hr·ft·°F
120 W/m·K69.3 BTU/hr·ft·°F

Max Service Temperature (continuous)

150°C302 °F
175°C347 °F

Same in both: Specific Heat Capacity 920 J/kg·K0.22 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 21 µm/m·K11.7 µin/in·°F · Latent Heat of Fusion 390 J/g168 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

30 % IACS
33 % IACS

Same in both: Electrical Resistivity 5.7×10⁻⁸ Ω·m2.24 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

33 / 100
38 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.68 V

Manufacturability

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

Machinability

78 / 100
80 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 200% · Weldability 25 / 100 · Formability (cold) 10 / 100 · Castability 40 / 100 · Brazeability / Solderability 20 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 205 MJ/kg88,134 BTU/lb · Embodied Carbon (primary production) 13 kg CO₂/kg · Embodied Water 1,150 L/kg138 gal/lb · Typical Recycled Content 10%

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 scaleEN AC-21000

EN AC-21000-T4 vs EN AC-21000-T6 — frequently asked

Is EN AC-21000-T6 stronger than EN AC-21000-T4?

Yes. EN AC-21000-T6 has a typical yield strength of 320 MPa (46.4 ksi) against 210 MPa (30.5 ksi) for EN AC-21000-T4 — about 52% more. Tensile strength is 390 MPa (56.6 ksi) vs 320 MPa (46.4 ksi).

Which condition does FabDigit quote by default, T4 or T6?

T4 is the default EN AC-21000 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 EN AC-21000-T4 over EN AC-21000-T6?

Pick EN AC-21000-T4 when the part is bent, formed or impact-loaded. Pick EN AC-21000-T6 when strength drives the design, or when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in EN AC-21000-T4 and EN AC-21000-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.