Refractory Metal Pure Mo vs Pure Nb
Refractory Metal · grade comparison
Refractory Metal Pure Mo and Pure Nb are both refractory metal grades, both vacuum refractory. Pure Mo is the stronger of the two: yield strength 590 MPa (85.6 ksi) against 125 MPa (18.1 ksi) for Pure Nb, about 4.7 times as much; tensile strength follows at 700 MPa (102 ksi) vs 220 MPa (31.9 ksi). In exchange, Pure Nb is the more ductile: elongation 40% versus 10% for Pure Mo, and Pure Mo is harder (240 HB vs 80 HB). Pure Nb is lighter (8.57 g/cm³ vs 10.22 g/cm³ for Pure Mo) and Pure Mo is stiffer (320 GPa vs 103 GPa). On the shop floor, Pure Mo machines more easily (fair vs poor) and Pure Nb welds better (very good vs poor).
Pure MoChoose it when strength drives the design, or when the part sees heat.
Pure NbChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
Pure Mo vs Pure Nb: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all refractory metal 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 refractory metal 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.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
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.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Castability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
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 refractory metal grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | Pure Mo | Pure Nb |
|---|---|---|
| Default condition | — | Vacuum Annealed |
| Relative cost | $$$$$ Specialty | $$$$$ Specialty |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Pure Mo vs Pure Nb — frequently asked
Is Pure Mo stronger than Pure Nb?
Yes. Pure Mo has a typical yield strength of 590 MPa (85.6 ksi) against 125 MPa (18.1 ksi) for Pure Nb — about 4.7 times as much. Tensile strength is 700 MPa (102 ksi) vs 220 MPa (31.9 ksi).
Which is cheaper, Pure Mo or Pure Nb?
Both sit in the same relative cost tier ($$$$$, specialty); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Pure Mo or Pure Nb?
Pure Mo. Its machinability rates fair (40/100) against poor (28/100) for Pure Nb; for welding the order is Pure Nb first (very good, 80/100) then Pure Mo (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Pure Mo and Pure Nb 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.