Magnesium Alloy EV31A vs ZM4
Magnesium Alloy · grade comparison
Magnesium Alloy EV31A and ZM4 are both magnesium alloy grades. EV31A is the stronger of the two: yield strength 110 MPa (16 ksi) against 100 MPa (14.5 ksi) for ZM4, about 10% more; tensile strength follows at 195 MPa (28.3 ksi) vs 160 MPa (23.2 ksi). EV31A is the more ductile: elongation 4% versus 3% for ZM4. ZM4 runs hotter in service (175°C vs 150°C continuous) and ZM4 conducts electricity better (25 % IACS vs 9.5 % IACS). On the shop floor, EV31A welds better (very good vs good) and EV31A sits in a lower cost tier (standard, $$) than ZM4 (high, $$$$).
EV31AChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
ZM4Choose it when the part sees heat.
EV31A vs ZM4: 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.
Shear Modulus
Bulk Modulus
Poisson's Ratio
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, Vickers
Reduction in Area
Same in both: Elastic (Young's) Modulus 44 GPa6.4 Msi · Hardness, Brinell 55 HB
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Same in both: Liquidus Temperature 640°C1,184 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 1,000 J/kg·K0.24 BTU/lb·°F · Latent Heat of Fusion 370 J/g159 BTU/lb
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.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Same in both: Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 15%
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 | EV31A | ZM4 |
|---|---|---|
| CNC machining | Yes | — |
| Default condition | As Cast | — |
| Relative cost | $$ Standard | $$$$ High |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 0.8 µm | — |
| Anodizing Type II | Yes | — |
| Chem Film (Alodine) | Yes | — |
| E-Coating | Yes | — |
| Hard Anodize Type III w/ PTFE | Yes | — |
| Hard Anodizing Type III | Yes | — |
| Painting | Yes | — |
| Powder Coating | Yes | — |
EV31A vs ZM4 — frequently asked
Is EV31A stronger than ZM4?
Yes. EV31A has a typical yield strength of 110 MPa (16 ksi) against 100 MPa (14.5 ksi) for ZM4 — about 10% more. Tensile strength is 195 MPa (28.3 ksi) vs 160 MPa (23.2 ksi).
Which is cheaper, EV31A or ZM4?
EV31A is the lower-cost material: it sits in the standard tier ($$) while ZM4 is high ($$$$). 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, EV31A or ZM4?
EV31A. Its weldability rates very good (72/100) against good (60/100) for ZM4.
Ready to make it?
Upload a CAD file and FabDigit prices the part in EV31A and ZM4 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.