Aluminum 6066-O vs 6066-T6511
Aluminum · 6066 temper comparison
6066-O and 6066-T6511 are two conditions of the same aluminum grade, 6066: O (annealed) versus T6511 (T6, stress relieved by stretching, minor straightening). The chemistry is identical, so every difference below comes from the condition. 6066-T6511 is the stronger of the two: yield strength 359 MPa (52.1 ksi) against 83 MPa (12 ksi) for 6066-O, about 4.3 times as much; tensile strength follows at 395 MPa (57.3 ksi) vs 150 MPa (21.8 ksi). In exchange, 6066-O is the more ductile: elongation 18% versus 12% for 6066-T6511, and 6066-T6511 is harder (120 HB vs 43 HB). 6066-O runs hotter in service (200°C vs 150°C continuous). On the shop floor, 6066-T6511 machines more easily (very good vs fair).
6066-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
6066-T6511Choose it when strength drives the design, or when the part is machined in volume.
6066-O vs 6066-T6511: 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
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 69 GPa10 Msi · Shear Modulus 26 GPa3.8 Msi · Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.33 · Hardness, Vickers 126 HV
Physical
Density and transition temperatures.
Same in both: Density 2.72 g/cm³0.1 lb/in³ · Melting Point (Solidus) 563°C1,045 °F · Liquidus Temperature 646°C1,195 °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 900 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 23.2 µm/m·K12.9 µin/in·°F · Latent Heat of Fusion 395 J/g170 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) -0.82 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Same in both: Brazeability / Solderability 25 / 100 · Polishability 60 / 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 kg CO₂/kg · Embodied Water 1,200 L/kg144 gal/lb · Typical Recycled Content 30%
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.
6066-O vs 6066-T6511 — frequently asked
Is 6066-T6511 stronger than 6066-O?
Yes. 6066-T6511 has a typical yield strength of 359 MPa (52.1 ksi) against 83 MPa (12 ksi) for 6066-O — about 4.3 times as much. Tensile strength is 395 MPa (57.3 ksi) vs 150 MPa (21.8 ksi).
Which condition does FabDigit quote by default, O or T6511?
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, 6066-O or 6066-T6511?
6066-T6511. Its machinability rates very good (75/100) against fair (45/100) for 6066-O; for welding the order is 6066-O first (fair, 45/100) then 6066-T6511 (fair, 40/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 6066-O and 6066-T6511 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.