Aluminum 6061 vs Magnesium Alloy AZ31B
Cross-family material comparison
Aluminum 6061 is an aluminum grade and Magnesium Alloy AZ31B is a magnesium alloy grade — different families, so density, stiffness and cost move together with strength. 6061 is the stronger of the two: yield strength 276 MPa (40 ksi) against 150 MPa (21.8 ksi) for AZ31B, about 84% more; tensile strength follows at 310 MPa (45 ksi) vs 255 MPa (37 ksi). In exchange, AZ31B is the more ductile: elongation 21% versus 12% for 6061, and 6061 is harder (95 HB vs 49 HB). AZ31B is lighter (1.77 g/cm³ vs 2.7 g/cm³ for 6061) and 6061 is stiffer (68.9 GPa vs 45 GPa). On the shop floor, AZ31B machines more easily (excellent vs very good), 6061 welds better (excellent vs very good), and 6061 sits in a lower cost tier (budget, $) than AZ31B (standard, $$).
6061Choose it when strength drives the design, or when the part sees heat.
AZ31BChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
6061 vs AZ31B: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all grades of the two families 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 grades of the two families 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
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Machinability Rating (AISI 1212 = 100 %)
Castability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
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 grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | 6061 | AZ31B |
|---|---|---|
| Default condition | T6 | O |
| Relative cost | $ Budget | $$ Standard |
| Min. machined wall | 0.5 mm | 0.8 mm |
| Best machined surface | Ra 0.8 µm | Ra 0.8 µm |
| Cerakote | Yes | — |
| DLC | Yes | — |
| Electroless Nickel (EN) | Yes | — |
| Electropolishing | Yes | — |
| Epoxy Coating | Yes | — |
| Gold Plating | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Silver Plating | Yes | — |
Both are offered for CNC machining and Sheet metal. They share 7 finishes: Anodizing Type II, Chem Film (Alodine), E-Coating, Hard Anodize Type III w/ PTFE, Hard Anodizing Type III, Painting, Powder Coating.
6061 vs AZ31B — frequently asked
Is 6061 stronger than AZ31B?
Yes. 6061 has a typical yield strength of 276 MPa (40 ksi) against 150 MPa (21.8 ksi) for AZ31B — about 84% more. Tensile strength is 310 MPa (45 ksi) vs 255 MPa (37 ksi).
Which is cheaper, 6061 or AZ31B?
6061 is the lower-cost material: it sits in the budget tier ($) while AZ31B is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, 6061 or AZ31B?
AZ31B. Its machinability rates excellent (95/100) against very good (70/100) for 6061; for welding the order is 6061 first (excellent, 85/100) then AZ31B (very good, 70/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 6061 and AZ31B 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.