Magnesium Alloy EQ21A vs EV31A
Magnesium Alloy · grade comparison
Magnesium Alloy EQ21A and EV31A are both magnesium alloy grades. EQ21A is the stronger of the two: yield strength 195 MPa (28.3 ksi) against 110 MPa (16 ksi) for EV31A, about 77% more; tensile strength follows at 260 MPa (37.7 ksi) vs 195 MPa (28.3 ksi). EQ21A is harder — 80 HB against 55 HB for EV31A — which matters for wear surfaces and threads. EQ21A runs hotter in service (200°C vs 150°C continuous) and EQ21A conducts heat better (113 W/m·K vs 100 W/m·K). On the shop floor, EV31A sits in a lower cost tier (standard, $$) than EQ21A (high, $$$$).
EQ21AChoose it when strength drives the design, or when surface hardness matters.
EV31AChoose it when cost is the deciding factor.
EQ21A vs EV31A: 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
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 44 GPa6.4 Msi · Shear Modulus 17 GPa2.5 Msi · Elongation at Break 4% · Charpy V-Notch Impact (RT) 3 J2.2 ft·lbf
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
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 1,000 J/kg·K0.24 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 26.7 µm/m·K14.8 µin/in·°F · Min Service Temperature -196°C-321 °F
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)
Same in both: Castability 85 / 100 · Brazeability / Solderability 20 / 100 · 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 | EQ21A | EV31A |
|---|---|---|
| CNC machining | — | Yes |
| Default condition | — | As Cast |
| Relative cost | $$$$ High | $$ Standard |
| 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 |
EQ21A vs EV31A — frequently asked
Is EQ21A stronger than EV31A?
Yes. EQ21A has a typical yield strength of 195 MPa (28.3 ksi) against 110 MPa (16 ksi) for EV31A — about 77% more. Tensile strength is 260 MPa (37.7 ksi) vs 195 MPa (28.3 ksi).
Which is cheaper, EQ21A or EV31A?
EV31A is the lower-cost material: it sits in the standard tier ($$) while EQ21A is high ($$$$). 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 EQ21A over EV31A?
Pick EQ21A when strength drives the design, or when surface hardness matters. Pick EV31A when cost is the deciding factor.
Ready to make it?
Upload a CAD file and FabDigit prices the part in EQ21A and EV31A 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.