Aluminum 7040-T6 vs 7040-T7351
Aluminum · 7040 temper comparison
7040-T6 and 7040-T7351 are two conditions of the same aluminum grade, 7040: T6 (solution heat treated and artificially aged) versus T7351 (T73, stress relieved by stretching). The chemistry is identical, so every difference below comes from the condition. 7040-T6 is the stronger of the two: yield strength 510 MPa (74 ksi) against 425 MPa (61.6 ksi) for 7040-T7351, about 20% more; tensile strength follows at 570 MPa (82.7 ksi) vs 490 MPa (71.1 ksi). In exchange, 7040-T7351 is the more ductile: elongation 11% versus 8% for 7040-T6, and 7040-T6 is harder (165 HB vs 138 HB). 7040-T7351 runs hotter in service (125°C vs 100°C continuous) and 7040-T7351 conducts heat better (158 W/m·K vs 130 W/m·K).
7040-T6Choose it when strength drives the design.
7040-T7351Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
7040-T6 vs 7040-T7351: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 71 GPa10.3 Msi · Shear Modulus 26.9 GPa3.9 Msi · Bulk Modulus 75 GPa10.9 Msi · Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Same in both: Density 2.82 g/cm³0.1 lb/in³ · Melting Point (Solidus) 480°C896 °F · Liquidus Temperature 635°C1,175 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 860 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
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.84 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Formability (cold)
Same in both: Machinability Rating (AISI 1212 = 100 %) 90% · Weldability 20 / 100 · Brazeability / Solderability 10 / 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 1,200 L/kg144 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.
7040-T6 vs 7040-T7351 — frequently asked
Is 7040-T6 stronger than 7040-T7351?
Yes. 7040-T6 has a typical yield strength of 510 MPa (74 ksi) against 425 MPa (61.6 ksi) for 7040-T7351 — about 20% more. Tensile strength is 570 MPa (82.7 ksi) vs 490 MPa (71.1 ksi).
Which condition does FabDigit quote by default, T6 or T7351?
T7451 is the default 7040 condition in the FabDigit quote flow (neither T6 nor T7351). 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 7040-T6 over 7040-T7351?
Pick 7040-T6 when strength drives the design. Pick 7040-T7351 when the part is bent, formed or impact-loaded, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 7040-T6 and 7040-T7351 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.