Magnesium Alloy AZ31B vs MB3
Magnesium Alloy · grade comparison
Magnesium Alloy AZ31B and MB3 are both magnesium alloy grades. MB3 is the stronger of the two: yield strength 165 MPa (23.9 ksi) against 150 MPa (21.8 ksi) for AZ31B, about 10% more. In exchange, AZ31B is the more ductile: elongation 21% versus 12% for MB3, and MB3 is harder (55 HB vs 49 HB). AZ31B conducts electricity better (18.5 % IACS vs 16 % IACS). On the shop floor, AZ31B welds better (very good vs good) and AZ31B sits in a lower cost tier (standard, $$) than MB3 (premium, $$$).
AZ31BChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
MB3Choose it when strength drives the design.
AZ31B vs MB3: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all magnesium alloy 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 magnesium alloy 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.
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Reduction in Area
Same in both: Elastic (Young's) Modulus 45 GPa6.5 Msi · Shear Modulus 17 GPa2.5 Msi · Poisson's Ratio 0.35
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
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Expansion (CTE, 20–100 °C) 26 µm/m·K14.4 µin/in·°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) -1.55 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Same in both: Machinability 95 / 100 · Machinability Rating (AISI 1212 = 100 %) 400% · Polishability 55 / 100
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 magnesium alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | AZ31B | MB3 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | O | — |
| Relative cost | $$ Standard | $$$ Premium |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 0.8 µm | — |
| Anodizing Type II | Yes | — |
| Chem Film (Alodine) | Yes | — |
| E-Coating | Yes | — |
| Hard Anodize Type III w/ PTFE | Yes | — |
| Hard Anodizing Type III | Yes | — |
| Painting | Yes | — |
| Powder Coating | Yes | — |
AZ31B vs MB3 — frequently asked
Is MB3 stronger than AZ31B?
Yes. MB3 has a typical yield strength of 165 MPa (23.9 ksi) against 150 MPa (21.8 ksi) for AZ31B — about 10% more. Tensile strength is 260 MPa (37.7 ksi) vs 255 MPa (37 ksi).
Which is cheaper, AZ31B or MB3?
AZ31B is the lower-cost material: it sits in the standard tier ($$) while MB3 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which welds better, AZ31B or MB3?
AZ31B. Its weldability rates very good (70/100) against good (60/100) for MB3.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AZ31B and MB3 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.