FabDigitFabDigit

Aluminum EN AC-21100-T4 vs EN AC-21100-T6

Aluminum · EN AC-21100 temper comparison

EN AC-21100-T4 and EN AC-21100-T6 are two conditions of the same aluminum grade, EN AC-21100: 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-21100-T6 is the stronger of the two: yield strength 210 MPa (30.5 ksi) against 165 MPa (23.9 ksi) for EN AC-21100-T4, about 27% more; tensile strength follows at 320 MPa (46.4 ksi) vs 290 MPa (42.1 ksi). In exchange, EN AC-21100-T4 is the more ductile: elongation 14% versus 6% for EN AC-21100-T6, and EN AC-21100-T6 is harder (95 HB vs 75 HB). EN AC-21100-T6 runs hotter in service (200°C vs 120°C continuous).

EN AC-21100-T4Choose it when the part is bent, formed or impact-loaded.

EN AC-21100-T6Choose it when strength drives the design, or when the part sees heat.

EN AC-21100-T4 vs EN AC-21100-T6: properties

EN AC-21100-T4EN AC-21100-T6

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

290 MPa42.1 ksi
320 MPa46.4 ksi

Yield Strength (0.2% offset)

165 MPa23.9 ksi
210 MPa30.5 ksi

Elongation at Break

14%
6%

Fatigue Strength (Endurance Limit)

85 MPa12.3 ksi
90 MPa13.1 ksi

Fracture Toughness (K_IC)

30 MPa·√m27.3 ksi·√in
24 MPa·√m21.8 ksi·√in

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
12 J8.9 ft·lbf

Hardness, Brinell

75 HB
95 HB

Same in both: Elastic (Young's) Modulus 72 GPa10.4 Msi · Shear Modulus 27 GPa3.9 Msi · Bulk Modulus 71 GPa10.3 Msi · Poisson's Ratio 0.33 · Compressive Strength 215 MPa31.2 ksi · Shear Strength 205 MPa29.7 ksi · Hardness, Vickers 100 HV

Physical

Density and transition temperatures.

Same in both: Density 2.75 g/cm³0.1 lb/in³ · Melting Point (Solidus) 545°C1,013 °F · Liquidus Temperature 650°C1,202 °F

Thermal

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

Thermal Conductivity

130 W/m·K75.1 BTU/hr·ft·°F
135 W/m·K78 BTU/hr·ft·°F

Max Service Temperature (continuous)

120°C248 °F
200°C392 °F

Same in both: Specific Heat Capacity 900 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 22.5 µm/m·K12.5 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 5.2×10⁻⁸ Ω·m2.05 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.69 V · Corrosion Resistance 35 / 100

Manufacturability

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

Machinability

75 / 100
80 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 200% · Weldability 25 / 100 · Formability (cold) 15 / 100 · Castability 40 / 100 · Brazeability / Solderability 20 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 150 MJ/kg64,488 BTU/lb · Embodied Carbon (primary production) 9.5 kg CO₂/kg · Embodied Water 1,100 L/kg132 gal/lb · Typical Recycled Content 25%

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-21100

EN AC-21100-T4 vs EN AC-21100-T6 — frequently asked

Is EN AC-21100-T6 stronger than EN AC-21100-T4?

Yes. EN AC-21100-T6 has a typical yield strength of 210 MPa (30.5 ksi) against 165 MPa (23.9 ksi) for EN AC-21100-T4 — about 27% more. Tensile strength is 320 MPa (46.4 ksi) vs 290 MPa (42.1 ksi).

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

T6 is the default EN AC-21100 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, EN AC-21100-T4 or EN AC-21100-T6?

EN AC-21100-T6, by a small margin. Both rate very good for machinability — 80/100 against 75/100 for EN AC-21100-T4.

Ready to make it?

Upload a CAD file and FabDigit prices the part in EN AC-21100-T4 and EN AC-21100-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.