Aluminum 2011-T4 vs 2011-T651
Aluminum · 2011 temper comparison
2011-T4 and 2011-T651 are two conditions of the same aluminum grade, 2011: T4 (solution heat treated and naturally aged) versus T651 (T6, stress relieved by stretching). The chemistry is identical, so every difference below comes from the condition. 2011-T651 is the stronger of the two: yield strength 290 MPa (42.1 ksi) against 193 MPa (28 ksi) for 2011-T4, about 50% more; tensile strength follows at 385 MPa (55.8 ksi) vs 324 MPa (47 ksi). In exchange, 2011-T4 is the more ductile: elongation 18% versus 12% for 2011-T651, and 2011-T651 is harder (100 HB vs 85 HB). 2011-T651 runs hotter in service (150°C vs 120°C continuous) and 2011-T651 conducts heat better (170 W/m·K vs 152 W/m·K). On the shop floor, 2011-T651 machines more easily (100 vs 90 out of 100).
2011-T4Choose it when the part is bent, formed or impact-loaded.
2011-T651Choose it when strength drives the design, or when the part sees heat.
2011-T4 vs 2011-T651: 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
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 70 GPa10.2 Msi · Shear Modulus 26 GPa3.8 Msi · Bulk Modulus 69 GPa10 Msi · Poisson's Ratio 0.33 · Fatigue Strength (Endurance Limit) 124 MPa18 ksi
Physical
Density and transition temperatures.
Same in both: Density 2.83 g/cm³0.1 lb/in³ · Melting Point (Solidus) 541°C1,006 °F · Liquidus Temperature 643°C1,189 °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 864 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 22.9 µm/m·K12.7 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).
Same in both: Galvanic Potential (seawater, vs SCE) -0.69 V · Corrosion Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 10 / 100 · Brazeability / Solderability 10 / 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 1,100 L/kg132 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.
2011-T4 vs 2011-T651 — frequently asked
Is 2011-T651 stronger than 2011-T4?
Yes. 2011-T651 has a typical yield strength of 290 MPa (42.1 ksi) against 193 MPa (28 ksi) for 2011-T4 — about 50% more. Tensile strength is 385 MPa (55.8 ksi) vs 324 MPa (47 ksi).
Which condition does FabDigit quote by default, T4 or T651?
Specify the condition in the material field or the drawing note; FabDigit prices the quote for the state you call out.
Which is easier to machine, 2011-T4 or 2011-T651?
2011-T651, by a small margin. Both rate excellent for machinability — 100/100 against 90/100 for 2011-T4.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 2011-T4 and 2011-T651 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.