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Refractory Metal Zr-2.5Nb vs Zr 704C

Refractory Metal · grade comparison

Refractory Metal Zr-2.5Nb and Zr 704C are both refractory metal grades. Zr-2.5Nb is the stronger of the two: yield strength 430 MPa (62.4 ksi) against 300 MPa (43.5 ksi) for Zr 704C, about 43% more; tensile strength follows at 610 MPa (88.5 ksi) vs 450 MPa (65.3 ksi). Zr-2.5Nb is the more ductile: elongation 20% versus 13% for Zr 704C. Zr-2.5Nb conducts heat better (17.1 W/m·K vs 13 W/m·K).

Zr-2.5NbChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

Zr-2.5Nb vs Zr 704C: properties

Zr-2.5NbZr 704C

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

97 GPa14.1 Msi
99 GPa14.4 Msi

Bulk Modulus

98 GPa14.2 Msi
97 GPa14.1 Msi

Poisson's Ratio

0.35
0.34

Tensile Strength (Ultimate)

610 MPa88.5 ksi
450 MPa65.3 ksi

Yield Strength (0.2% offset)

430 MPa62.4 ksi
300 MPa43.5 ksi

Elongation at Break

20%
13%

Reduction in Area

42%
20%

Compressive Strength

400 MPa58 ksi
320 MPa46.4 ksi

Shear Strength

370 MPa53.7 ksi
300 MPa43.5 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
200 MPa29 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
50 MPa·√m45.5 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
20 J14.8 ft·lbf

Hardness, Brinell

185 HB
190 HB

Hardness, Rockwell B

90 HRB
89 HRB

Same in both: Shear Modulus 36 GPa5.2 Msi · Hardness, Vickers 200 HV

Physical

Density and transition temperatures.

Density

6.55 g/cm³0.24 lb/in³
6.56 g/cm³0.24 lb/in³

Melting Point (Solidus)

1,840°C3,344 °F
1,800°C3,272 °F

Liquidus Temperature

1,860°C3,380 °F
1,845°C3,353 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

17.1 W/m·K9.9 BTU/hr·ft·°F
13 W/m·K7.5 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

6.3 µm/m·K3.5 µin/in·°F
6 µm/m·K3.3 µin/in·°F

Min Service Temperature

-196°C-321 °F
-75°C-103 °F

Same in both: Specific Heat Capacity 285 J/kg·K0.07 BTU/lb·°F · Latent Heat of Fusion 155 J/g66.6 BTU/lb · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

3.1 % IACS
2.5 % IACS

Electrical Resistivity

5.5×10⁻⁷ Ω·m21.7 µΩ·in
6.8×10⁻⁷ Ω·m26.8 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

91 / 100
90 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.15 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

32 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

22%
28%

Weldability

70 / 100
65 / 100

Formability (cold)

55 / 100
20 / 100

Castability

30 / 100
55 / 100

Brazeability / Solderability

25 / 100
20 / 100

Same in both: Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

1,300 MJ/kg558,900 BTU/lb
1,200 MJ/kg515,908 BTU/lb

Embodied Carbon (primary production)

80 kg CO₂/kg
75 kg CO₂/kg

Embodied Water

700 L/kg83.9 gal/lb
900 L/kg108 gal/lb

Typical Recycled Content

10%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

93 kN·m/kg
69 kN·m/kg

Specific Stiffness (E / density)

14.8 MN·m/kg
15.1 MN·m/kg

Modulus of Resilience

953 kJ/m³
455 kJ/m³

Thermal Diffusivity

9.2 mm²/s
7 mm²/s

Thermal Shock Resistance Index

17
10

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.

1502003005007001,0001,5005101520Density (g/cm³)Yield strength (MPa) — log scaleZr 704CZr-2.5Nb

Manufacturing and finishing

CapabilityZr-2.5NbZr 704C
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Zr-2.5Nb vs Zr 704C — frequently asked

Is Zr-2.5Nb stronger than Zr 704C?

Yes. Zr-2.5Nb has a typical yield strength of 430 MPa (62.4 ksi) against 300 MPa (43.5 ksi) for Zr 704C — about 43% more. Tensile strength is 610 MPa (88.5 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, Zr-2.5Nb or Zr 704C?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which welds better, Zr-2.5Nb or Zr 704C?

Zr-2.5Nb. Its weldability rates very good (70/100) against good (65/100) for Zr 704C.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Zr-2.5Nb and Zr 704C 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.