Aluminum 6201-O vs 6201-T81
Aluminum · 6201 temper comparison
6201-O and 6201-T81 are two conditions of the same aluminum grade, 6201: O (annealed) versus T81 (solution heat treated, cold worked (drawn), artificially aged). The chemistry is identical, so every difference below comes from the condition. 6201-T81 is the stronger of the two: yield strength 310 MPa (45 ksi) against 75 MPa (10.9 ksi) for 6201-O, about 4.1 times as much; tensile strength follows at 330 MPa (47.9 ksi) vs 145 MPa (21 ksi). In exchange, 6201-O is the more ductile: elongation 22% versus 4% for 6201-T81, and 6201-T81 is harder (100 HB vs 40 HB). 6201-O runs hotter in service (150°C vs 90°C continuous). On the shop floor, 6201-T81 machines more easily (good vs fair).
6201-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
6201-T81Choose it when strength drives the design, or when the part is machined in volume.
6201-O vs 6201-T81: 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 68.9 GPa10 Msi · Shear Modulus 26 GPa3.8 Msi · Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.33 · Fatigue Strength (Endurance Limit) 100 MPa14.5 ksi · Fracture Toughness (K_IC) 29 MPa·√m26.4 ksi·√in
Physical
Density and transition temperatures.
Same in both: Density 2.69 g/cm³0.1 lb/in³ · Melting Point (Solidus) 607°C1,125 °F · Liquidus Temperature 654°C1,209 °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 895 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 23 µm/m·K12.8 µin/in·°F · Latent Heat of Fusion 393 J/g169 BTU/lb · Min Service Temperature -80°C-112 °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) -0.83 V · Corrosion Resistance 68 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Formability (cold)
Same in both: Weldability 62 / 100 · Brazeability / Solderability 55 / 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 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.
6201-O vs 6201-T81 — frequently asked
Is 6201-T81 stronger than 6201-O?
Yes. 6201-T81 has a typical yield strength of 310 MPa (45 ksi) against 75 MPa (10.9 ksi) for 6201-O — about 4.1 times as much. Tensile strength is 330 MPa (47.9 ksi) vs 145 MPa (21 ksi).
Which condition does FabDigit quote by default, O or T81?
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, 6201-O or 6201-T81?
6201-T81. Its machinability rates good (65/100) against fair (40/100) for 6201-O.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 6201-O and 6201-T81 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.