Aluminum 6063 vs 6081
Aluminum · grade comparison
Aluminum 6063 and 6081 are both aluminum grades, both multipurpose al. 6081 is the stronger of the two: yield strength 275 MPa (39.9 ksi) against 214 MPa (31 ksi) for 6063, about 29% more; tensile strength follows at 310 MPa (45 ksi) vs 241 MPa (35 ksi). 6081 is harder — 95 HB against 73 HB for 6063 — which matters for wear surfaces and threads. 6063 conducts heat better (200 W/m·K vs 170 W/m·K). On the shop floor, 6063 welds better (excellent vs very good).
6063Choose it when it will be welded.
6081Choose it when strength drives the design, or when surface hardness matters.
6063 vs 6081: 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.
Elastic (Young's) Modulus
Shear Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Vickers
Compressive Strength
Same in both: Bulk Modulus 69 GPa10 Msi · Poisson's Ratio 0.33 · Fracture Toughness (K_IC) 29 MPa·√m26.4 ksi·√in
Physical
Density and transition temperatures.
Melting Point (Solidus)
Liquidus Temperature
Same in both: Density 2.7 g/cm³0.1 lb/in³
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Latent Heat of Fusion
Same in both: Specific Heat Capacity 900 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 23.4 µm/m·K13 µin/in·°F · Max Service Temperature (continuous) 150°C302 °F · 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) -0.83 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Brazeability / Solderability
Polishability
Castability
Same in both: Formability (cold) 40 / 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 1,200 L/kg144 gal/lb · Typical Recycled Content 35%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 6063 | 6081 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $ Budget | $ Budget |
| Min. machined wall | 0.5 mm | 0.5 mm |
| Best machined surface | Ra 0.8 µm | Ra 0.8 µm |
Both are offered for CNC machining and Sheet metal. Both take the same 16 finishes: Anodizing Type II, Cerakote, Chem Film (Alodine), DLC, E-Coating, Electroless Nickel (EN), Electropolishing, Epoxy Coating, Gold Plating, Hard Anodize Type III w/ PTFE, Hard Anodizing Type III, Nickel Plating and 4 more.
6063 vs 6081 — frequently asked
Is 6081 stronger than 6063?
Yes. 6081 has a typical yield strength of 275 MPa (39.9 ksi) against 214 MPa (31 ksi) for 6063 — about 29% more. Tensile strength is 310 MPa (45 ksi) vs 241 MPa (35 ksi).
Which is cheaper, 6063 or 6081?
Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 6063 or 6081?
6081, by a small margin. Both rate good for machinability — 60/100 against 55/100 for 6063; for welding the order is 6063 first (excellent, 90/100) then 6081 (very good, 78/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 6063 and 6081 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.