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Magnesium Alloy AZ91D vs AZ92A

Magnesium Alloy · grade comparison

Magnesium Alloy AZ91D and AZ92A are both magnesium alloy grades. AZ91D is the stronger of the two: yield strength 160 MPa (23.2 ksi) against 145 MPa (21 ksi) for AZ92A, about 10% more. AZ92A is harder — 84 HB against 63 HB for AZ91D — which matters for wear surfaces and threads. AZ92A runs hotter in service (150°C vs 120°C continuous). On the shop floor, AZ92A welds better (good vs fair) and AZ91D sits in a lower cost tier (standard, $$) than AZ92A (premium, $$$).

AZ91DChoose it when strength drives the design, or when cost is the deciding factor.

AZ92AChoose it when surface hardness matters, or when the part sees heat.

AZ91D vs AZ92A: properties

AZ91DAZ92A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

230 MPa33.4 ksi
275 MPa39.9 ksi

Yield Strength (0.2% offset)

160 MPa23.2 ksi
145 MPa21 ksi

Compressive Strength

165 MPa23.9 ksi
345 MPa50 ksi

Shear Strength

140 MPa20.3 ksi
152 MPa22 ksi

Fatigue Strength (Endurance Limit)

97 MPa14.1 ksi
76 MPa11 ksi

Charpy V-Notch Impact (RT)

2 J1.6 ft·lbf
1 J1 ft·lbf

Hardness, Brinell

63 HB
84 HB

Hardness, Vickers

75 HV
—

Same in both: Elastic (Young's) Modulus 45 GPa6.5 Msi · Shear Modulus 17 GPa2.5 Msi · Bulk Modulus 45 GPa6.5 Msi · Poisson's Ratio 0.35 · Elongation at Break 3% · Fracture Toughness (K_IC) 13 MPa·√m11.8 ksi·√in

Physical

Density and transition temperatures.

Density

1.81 g/cm³0.07 lb/in³
1.82 g/cm³0.07 lb/in³

Melting Point (Solidus)

470°C878 °F
443°C829 °F

Liquidus Temperature

595°C1,103 °F
596°C1,105 °F

Thermal

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

Specific Heat Capacity

1,020 J/kg·K0.24 BTU/lb·°F
1,050 J/kg·K0.25 BTU/lb·°F

Max Service Temperature (continuous)

120°C248 °F
150°C302 °F

Min Service Temperature

-60°C-76 °F
-50°C-58 °F

Same in both: Thermal Conductivity 72 W/m·K41.6 BTU/hr·ft·°F · Thermal Expansion (CTE, 20–100 °C) 26 µm/m·K14.4 µin/in·°F · Latent Heat of Fusion 373 J/g160 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

12.2 % IACS
11.5 % IACS

Electrical Resistivity

1.41×10⁻⁷ Ω·m5.55 µΩ·in
1.49×10⁻⁷ Ω·m5.87 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

30 / 100
22 / 100

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.

Machinability

98 / 100
97 / 100

Weldability

40 / 100
55 / 100

Formability (cold)

15 / 100
10 / 100

Castability

92 / 100
85 / 100

Brazeability / Solderability

20 / 100
25 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 400% · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

320 MJ/kg137,575 BTU/lb
350 MJ/kg150,473 BTU/lb

Embodied Carbon (primary production)

32 kg CO₂/kg
30 kg CO₂/kg

Typical Recycled Content

35%
25%

Same in both: Embodied Water 500 L/kg59.9 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

127 kN·m/kg
151 kN·m/kg

Specific Stiffness (E / density)

24.9 MN·m/kg
24.7 MN·m/kg

Modulus of Resilience

284 kJ/m³
234 kJ/m³

Thermal Diffusivity

39 mm²/s
37.7 mm²/s

Thermal Shock Resistance Index

14
17

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 scaleAZ91DAZ92A

Manufacturing and finishing

CapabilityAZ91DAZ92A
CNC machiningYes—
Casting & forgingYes—
Default conditionAs Cast—
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—

AZ91D vs AZ92A — frequently asked

Is AZ91D stronger than AZ92A?

Yes. AZ91D has a typical yield strength of 160 MPa (23.2 ksi) against 145 MPa (21 ksi) for AZ92A — about 10% more. Tensile strength is 230 MPa (33.4 ksi) vs 275 MPa (39.9 ksi).

Which is cheaper, AZ91D or AZ92A?

AZ91D is the lower-cost material: it sits in the standard tier ($$) while AZ92A is premium ($$$). 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, AZ91D or AZ92A?

AZ92A. Its weldability rates good (55/100) against fair (40/100) for AZ91D.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AZ91D and AZ92A 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.