Magnesium Alloy AZ31B vs K1A
Magnesium Alloy · grade comparison
Magnesium Alloy AZ31B and K1A are both magnesium alloy grades. AZ31B is the stronger of the two: yield strength 150 MPa (21.8 ksi) against 55 MPa (7.98 ksi) for K1A, about 173% more; tensile strength follows at 255 MPa (37 ksi) vs 180 MPa (26.1 ksi). AZ31B is harder — 49 HB against 40 HB for K1A — which matters for wear surfaces and threads. K1A runs hotter in service (150°C vs 120°C continuous) and K1A conducts heat better (130 W/m·K vs 96 W/m·K). On the shop floor, AZ31B forms better (fair vs poor) and AZ31B sits in a lower cost tier (standard, $$) than K1A (premium, $$$).
AZ31BChoose it when strength drives the design, or when surface hardness matters.
K1AChoose it when the part sees heat.
AZ31B vs K1A: 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
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
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.
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Same in both: Machinability 95 / 100 · Machinability Rating (AISI 1212 = 100 %) 400% · Weldability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 500 L/kg59.9 gal/lb
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 | K1A |
|---|---|---|
| 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 K1A — frequently asked
Is AZ31B stronger than K1A?
Yes. AZ31B has a typical yield strength of 150 MPa (21.8 ksi) against 55 MPa (7.98 ksi) for K1A — about 173% more. Tensile strength is 255 MPa (37 ksi) vs 180 MPa (26.1 ksi).
Which is cheaper, AZ31B or K1A?
AZ31B is the lower-cost material: it sits in the standard tier ($$) while K1A is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
When should I choose AZ31B over K1A?
Pick AZ31B when strength drives the design, or when surface hardness matters. Pick K1A when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AZ31B and K1A 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.