Aluminum ZL205A-T4 vs ZL205A-T7
Aluminum · ZL205A temper comparison
ZL205A-T4 and ZL205A-T7 are two conditions of the same aluminum grade, ZL205A: T4 (solution heat treated and naturally aged) versus T7 (solution heat treated and overaged (stabilized)). The chemistry is identical, so every difference below comes from the condition. ZL205A-T7 is the stronger of the two: yield strength 360 MPa (52.2 ksi) against 250 MPa (36.3 ksi) for ZL205A-T4, about 44% more; tensile strength follows at 470 MPa (68.2 ksi) vs 400 MPa (58 ksi). In exchange, ZL205A-T4 is the more ductile: elongation 13% versus 3% for ZL205A-T7, and ZL205A-T7 is harder (112 HB vs 90 HB). ZL205A-T7 runs hotter in service (200°C vs 120°C continuous) and ZL205A-T7 conducts heat better (168 W/m·K vs 130 W/m·K).
ZL205A-T4Choose it when the part is bent, formed or impact-loaded.
ZL205A-T7Choose it when strength drives the design, or when the part sees heat.
ZL205A-T4 vs ZL205A-T7: 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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
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
Physical
Density and transition temperatures.
Same in both: Density 2.82 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
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 880 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
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.73 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 40 / 100 · Brazeability / Solderability 25 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12.5 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.
ZL205A-T4 vs ZL205A-T7 — frequently asked
Is ZL205A-T7 stronger than ZL205A-T4?
Yes. ZL205A-T7 has a typical yield strength of 360 MPa (52.2 ksi) against 250 MPa (36.3 ksi) for ZL205A-T4 — about 44% more. Tensile strength is 470 MPa (68.2 ksi) vs 400 MPa (58 ksi).
Which condition does FabDigit quote by default, T4 or T7?
T5 is the default ZL205A condition in the FabDigit quote flow (neither T4 nor T7). 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, ZL205A-T4 or ZL205A-T7?
ZL205A-T7. Its machinability rates very good (76/100) against good (68/100) for ZL205A-T4; for welding the order is ZL205A-T4 first (fair, 45/100) then ZL205A-T7 (fair, 40/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in ZL205A-T4 and ZL205A-T7 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.