Aluminum 7129-T4 vs 7129-T6
Aluminum · 7129 temper comparison
7129-T4 and 7129-T6 are two conditions of the same aluminum grade, 7129: 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. 7129-T6 is the stronger of the two: yield strength 350 MPa (50.8 ksi) against 210 MPa (30.5 ksi) for 7129-T4, about 67% more; tensile strength follows at 400 MPa (58 ksi) vs 330 MPa (47.9 ksi). In exchange, 7129-T4 is the more ductile: elongation 18% versus 11% for 7129-T6, and 7129-T6 is harder (120 HB vs 95 HB). On the shop floor, 7129-T6 machines more easily (good vs fair).
7129-T4Choose it when the part is bent, formed or impact-loaded.
7129-T6Choose it when strength drives the design, or when the part is machined in volume.
7129-T4 vs 7129-T6: 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
Shear Strength
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 70 GPa10.2 Msi · Shear Modulus 26.5 GPa3.8 Msi · Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.33 · Compressive Strength 355 MPa51.5 ksi · Fatigue Strength (Endurance Limit) 150 MPa21.8 ksi · Fracture Toughness (K_IC) 30 MPa·√m27.3 ksi·√in · Hardness, Vickers 130 HV
Physical
Density and transition temperatures.
Same in both: Density 2.8 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
Same in both: Specific Heat Capacity 865 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 · Max Service Temperature (continuous) 120°C248 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Same in both: Electrical Resistivity 5.4×10⁻⁸ Ω·m2.13 µΩ·in
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 %) 70% · Weldability 30 / 100 · Brazeability / Solderability 15 / 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 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.
7129-T4 vs 7129-T6 — frequently asked
Is 7129-T6 stronger than 7129-T4?
Yes. 7129-T6 has a typical yield strength of 350 MPa (50.8 ksi) against 210 MPa (30.5 ksi) for 7129-T4 — about 67% more. Tensile strength is 400 MPa (58 ksi) vs 330 MPa (47.9 ksi).
Which condition does FabDigit quote by default, T4 or T6?
T6 is the default 7129 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, 7129-T4 or 7129-T6?
7129-T6. Its machinability rates good (62/100) against fair (50/100) for 7129-T4.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 7129-T4 and 7129-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.