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Magnesium Alloy AZ31B vs MB1

Magnesium Alloy · grade comparison

Magnesium Alloy AZ31B and MB1 are both magnesium alloy grades. AZ31B is the stronger of the two: yield strength 150 MPa (21.8 ksi) against 105 MPa (15.2 ksi) for MB1, about 43% more; tensile strength follows at 255 MPa (37 ksi) vs 225 MPa (32.6 ksi). AZ31B is the more ductile: elongation 21% versus 12% for MB1, and AZ31B is harder (49 HB vs 40 HB). MB1 runs hotter in service (150°C vs 120°C continuous) and MB1 conducts heat better (138 W/m·K vs 96 W/m·K). On the shop floor, MB1 welds better (excellent vs very good) and AZ31B sits in a lower cost tier (standard, $$) than MB1 (premium, $$$).

AZ31BChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

MB1Choose it when the part sees heat, or when it will be welded.

AZ31B vs MB1: properties

AZ31BMB1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

35 GPa5.1 Msi
36 GPa5.2 Msi

Tensile Strength (Ultimate)

255 MPa37 ksi
225 MPa32.6 ksi

Yield Strength (0.2% offset)

150 MPa21.8 ksi
105 MPa15.2 ksi

Elongation at Break

21%
12%

Compressive Strength

97 MPa14.1 ksi
75 MPa10.9 ksi

Shear Strength

145 MPa21 ksi
110 MPa16 ksi

Fatigue Strength (Endurance Limit)

125 MPa18.1 ksi
65 MPa9.4 ksi

Fracture Toughness (K_IC)

14 MPa·√m12.7 ksi·√in
15 MPa·√m13.7 ksi·√in

Charpy V-Notch Impact (RT)

5 J3.7 ft·lbf
—

Hardness, Brinell

49 HB
40 HB

Hardness, Rockwell B

45 HRB
—

Hardness, Vickers

55 HV
—

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

1.77 g/cm³0.06 lb/in³
1.76 g/cm³0.06 lb/in³

Melting Point (Solidus)

566°C1,051 °F
648°C1,198 °F

Liquidus Temperature

632°C1,170 °F
651°C1,204 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

96 W/m·K55.5 BTU/hr·ft·°F
138 W/m·K79.7 BTU/hr·ft·°F

Latent Heat of Fusion

340 J/g146 BTU/lb
370 J/g159 BTU/lb

Max Service Temperature (continuous)

120°C248 °F
150°C302 °F

Min Service Temperature

-80°C-112 °F
-60°C-76 °F

Same in both: Specific Heat Capacity 1,000 J/kg·K0.24 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 26 µm/m·K14.4 µin/in·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

18.5 % IACS
33 % IACS

Electrical Resistivity

9.2×10⁻⁸ Ω·m3.62 µΩ·in
5.2×10⁻⁸ Ω·m2.05 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-1.55 V
-1.6 V

Corrosion Resistance

25 / 100
22 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

95 / 100
93 / 100

Machinability Rating (AISI 1212 = 100 %)

400%
500%

Weldability

70 / 100
90 / 100

Formability (cold)

50 / 100
35 / 100

Castability

40 / 100
—

Polishability

55 / 100
45 / 100

Same in both: Brazeability / Solderability 25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

330 MJ/kg141,875 BTU/lb
300 MJ/kg128,977 BTU/lb

Embodied Carbon (primary production)

32 kg CO₂/kg
28 kg CO₂/kg

Same in both: Embodied Water 500 L/kg59.9 gal/lb · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

144 kN·m/kg
128 kN·m/kg

Specific Stiffness (E / density)

25.4 MN·m/kg
25.6 MN·m/kg

Modulus of Resilience

250 kJ/m³
123 kJ/m³

Thermal Diffusivity

54.2 mm²/s
78.4 mm²/s

Thermal Shock Resistance Index

21
27

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.

701001502001.41.51.61.71.8Density (g/cm³)Yield strength (MPa) — log scaleAZ31BMB1

Manufacturing and finishing

CapabilityAZ31BMB1
CNC machiningYes—
Sheet metalYes—
Default conditionO—
Relative cost$$ Standard$$$ Premium
Min. machined wall0.8 mm—
Best machined surfaceRa 0.8 µm—
Anodizing Type IIYes—
Chem Film (Alodine)Yes—
E-CoatingYes—
Hard Anodize Type III w/ PTFEYes—
Hard Anodizing Type IIIYes—
PaintingYes—
Powder CoatingYes—

AZ31B vs MB1 — frequently asked

Is AZ31B stronger than MB1?

Yes. AZ31B has a typical yield strength of 150 MPa (21.8 ksi) against 105 MPa (15.2 ksi) for MB1 — about 43% more. Tensile strength is 255 MPa (37 ksi) vs 225 MPa (32.6 ksi).

Which is cheaper, AZ31B or MB1?

AZ31B is the lower-cost material: it sits in the standard tier ($$) while MB1 is premium ($$$). 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 MB1?

MB1. Its weldability rates excellent (90/100) against very good (70/100) for AZ31B.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AZ31B and MB1 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.