Magnesium Alloy AZ31B-H22 vs AZ31B-O
Magnesium Alloy · AZ31B temper comparison
AZ31B-H22 and AZ31B-O are two conditions of the same magnesium alloy grade, AZ31B: H22 (strain hardened and partially annealed, quarter hard) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. AZ31B-H22 is the stronger of the two: yield strength 190 MPa (27.6 ksi) against 150 MPa (21.8 ksi) for AZ31B-O, about 27% more; tensile strength follows at 270 MPa (39.2 ksi) vs 255 MPa (37 ksi). In exchange, AZ31B-O is the more ductile: elongation 21% versus 17% for AZ31B-H22, and AZ31B-H22 is harder (65 HB vs 49 HB). AZ31B-O runs hotter in service (120°C vs 110°C continuous).
AZ31B-H22Choose it when strength drives the design.
AZ31B-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
AZ31B-H22 vs AZ31B-O: 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.
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
Same in both: Elastic (Young's) Modulus 45 GPa6.5 Msi · Shear Modulus 17 GPa2.5 Msi · Bulk Modulus 35 GPa5.1 Msi · Poisson's Ratio 0.35
Physical
Density and transition temperatures.
Same in both: Density 1.77 g/cm³0.06 lb/in³ · Melting Point (Solidus) 566°C1,051 °F · Liquidus Temperature 632°C1,170 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 96 W/m·K55.5 BTU/hr·ft·°F · 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 · Latent Heat of Fusion 340 J/g146 BTU/lb · Min Service Temperature -80°C-112 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 18.5 % IACS · Electrical Resistivity 9.2×10⁻⁸ Ω·m3.62 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -1.55 V · Corrosion Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Weldability
Formability (cold)
Polishability
Same in both: Machinability 95 / 100 · Machinability Rating (AISI 1212 = 100 %) 400% · Castability 40 / 100 · Brazeability / Solderability 25 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 330 MJ/kg141,875 BTU/lb · Embodied Carbon (primary production) 32 kg CO₂/kg · Embodied Water 500 L/kg59.9 gal/lb · Typical Recycled Content 25%
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.
AZ31B-H22 vs AZ31B-O — frequently asked
Is AZ31B-H22 stronger than AZ31B-O?
Yes. AZ31B-H22 has a typical yield strength of 190 MPa (27.6 ksi) against 150 MPa (21.8 ksi) for AZ31B-O — about 27% more. Tensile strength is 270 MPa (39.2 ksi) vs 255 MPa (37 ksi).
Which condition does FabDigit quote by default, H22 or O?
O is the default AZ31B condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
When should I choose AZ31B-H22 over AZ31B-O?
Pick AZ31B-H22 when strength drives the design. Pick AZ31B-O when the part is bent, formed or impact-loaded, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AZ31B-H22 and AZ31B-O 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.