Aluminum 2218-T6 vs 2218-T71
Aluminum · 2218 temper comparison
2218-T6 and 2218-T71 are two conditions of the same aluminum grade, 2218: T6 (solution heat treated and artificially aged) versus T71 (solution heat treated and overaged). The chemistry is identical, so every difference below comes from the condition. 2218-T6 is the stronger of the two: yield strength 305 MPa (44.2 ksi) against 275 MPa (39.9 ksi) for 2218-T71, about 11% more; tensile strength follows at 405 MPa (58.7 ksi) vs 345 MPa (50 ksi). 2218-T6 is harder — 115 HB against 105 HB for 2218-T71 — which matters for wear surfaces and threads. 2218-T71 runs hotter in service (230°C vs 200°C continuous).
2218-T6Choose it when strength drives the design, or when surface hardness matters.
2218-T71Choose it when the part sees heat.
2218-T6 vs 2218-T71: 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)
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 74 GPa10.7 Msi · Shear Modulus 28 GPa4.1 Msi · Bulk Modulus 76 GPa11 Msi · Poisson's Ratio 0.33 · Elongation at Break 11% · Compressive Strength 310 MPa45 ksi
Physical
Density and transition temperatures.
Same in both: Density 2.81 g/cm³0.1 lb/in³ · Melting Point (Solidus) 505°C941 °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 865 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 22.4 µm/m·K12.4 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
Same in both: Electrical Resistivity 4.5×10⁻⁸ Ω·m1.77 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.66 V · Corrosion Resistance 33 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Same in both: Weldability 22 / 100 · Formability (cold) 28 / 100 · Brazeability / Solderability 18 / 100 · Polishability 55 / 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 20%
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.
2218-T6 vs 2218-T71 — frequently asked
Is 2218-T6 stronger than 2218-T71?
Yes. 2218-T6 has a typical yield strength of 305 MPa (44.2 ksi) against 275 MPa (39.9 ksi) for 2218-T71 — about 11% more. Tensile strength is 405 MPa (58.7 ksi) vs 345 MPa (50 ksi).
Which condition does FabDigit quote by default, T6 or T71?
T61 is the default 2218 condition in the FabDigit quote flow (neither T6 nor T71). 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 2218-T6 over 2218-T71?
Pick 2218-T6 when strength drives the design, or when surface hardness matters. Pick 2218-T71 when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 2218-T6 and 2218-T71 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.