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Aluminum 7204-T4 vs 7204-T6511

Aluminum · 7204 temper comparison

7204-T4 and 7204-T6511 are two conditions of the same aluminum grade, 7204: T4 (solution heat treated and naturally aged) versus T6511 (T6, stress relieved by stretching, minor straightening). The chemistry is identical, so every difference below comes from the condition. 7204-T6511 is the stronger of the two: yield strength 305 MPa (44.2 ksi) against 205 MPa (29.7 ksi) for 7204-T4, about 49% more; tensile strength follows at 355 MPa (51.5 ksi) vs 315 MPa (45.7 ksi). In exchange, 7204-T4 is the more ductile: elongation 16% versus 10% for 7204-T6511, and 7204-T6511 is harder (100 HB vs 78 HB). 7204-T6511 runs hotter in service (120°C vs 100°C continuous) and 7204-T6511 conducts electricity better (38 % IACS vs 34 % IACS). On the shop floor, 7204-T6511 machines more easily (good vs fair).

7204-T4Choose it when the part is bent, formed or impact-loaded.

7204-T6511Choose it when strength drives the design, or when the part sees heat.

7204-T4 vs 7204-T6511: properties

7204-T47204-T6511

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

315 MPa45.7 ksi
355 MPa51.5 ksi

Yield Strength (0.2% offset)

205 MPa29.7 ksi
305 MPa44.2 ksi

Elongation at Break

16%
10%

Compressive Strength

305 MPa44.2 ksi
310 MPa45 ksi

Shear Strength

195 MPa28.3 ksi
212 MPa30.7 ksi

Fatigue Strength (Endurance Limit)

130 MPa18.9 ksi
150 MPa21.8 ksi

Hardness, Brinell

78 HB
100 HB

Same in both: Elastic (Young's) Modulus 70 GPa10.2 Msi · Shear Modulus 26.5 GPa3.8 Msi · Bulk Modulus 69 GPa10 Msi · Poisson's Ratio 0.33 · Fracture Toughness (K_IC) 32 MPa·√m29.1 ksi·√in · Hardness, Vickers 110 HV

Physical

Density and transition temperatures.

Same in both: Density 2.78 g/cm³0.1 lb/in³ · Melting Point (Solidus) 605°C1,121 °F · Liquidus Temperature 645°C1,193 °F

Thermal

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

Thermal Conductivity

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

Max Service Temperature (continuous)

100°C212 °F
120°C248 °F

Same in both: Specific Heat Capacity 900 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 23.4 µm/m·K13 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

34 % IACS
38 % IACS

Electrical Resistivity

5.1×10⁻⁸ Ω·m2.01 µΩ·in
4.5×10⁻⁸ Ω·m1.77 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

52 / 100
58 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.86 V

Manufacturability

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

Machinability

48 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

130%
140%

Formability (cold)

55 / 100
30 / 100

Same in both: Weldability 82 / 100 · Castability 35 / 100 · Brazeability / Solderability 20 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 205 MJ/kg88,134 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg · Embodied Water 1,150 L/kg138 gal/lb · Typical Recycled Content 30%

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 scale7204

7204-T4 vs 7204-T6511 — frequently asked

Is 7204-T6511 stronger than 7204-T4?

Yes. 7204-T6511 has a typical yield strength of 305 MPa (44.2 ksi) against 205 MPa (29.7 ksi) for 7204-T4 — about 49% more. Tensile strength is 355 MPa (51.5 ksi) vs 315 MPa (45.7 ksi).

Which condition does FabDigit quote by default, T4 or T6511?

T6 is the default 7204 condition in the FabDigit quote flow (neither T4 nor T6511). 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, 7204-T4 or 7204-T6511?

7204-T6511. Its machinability rates good (62/100) against fair (48/100) for 7204-T4.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 7204-T4 and 7204-T6511 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.