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Refractory Metal Zr 704 vs Zr 704C

Refractory Metal · grade comparison

Refractory Metal Zr 704 and Zr 704C are both refractory metal grades. Both yield at about 300 MPa — strength does not separate them. Zr 704 is the more ductile: elongation 22% versus 13% for Zr 704C, and Zr 704C is harder (190 HB vs 180 HB). Zr 704 conducts heat better (14.6 W/m·K vs 13 W/m·K). On the shop floor, Zr 704 welds better (very good vs good).

Zr 704Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

Zr 704 vs Zr 704C: properties

Zr 704Zr 704C

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

100 GPa14.5 Msi
97 GPa14.1 Msi

Poisson's Ratio

0.35
0.34

Tensile Strength (Ultimate)

470 MPa68.2 ksi
450 MPa65.3 ksi

Elongation at Break

22%
13%

Reduction in Area

40%
20%

Compressive Strength

310 MPa45 ksi
320 MPa46.4 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
200 MPa29 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
50 MPa·√m45.5 ksi·√in

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
20 J14.8 ft·lbf

Hardness, Brinell

180 HB
190 HB

Hardness, Rockwell B

88 HRB
89 HRB

Hardness, Vickers

190 HV
200 HV

Same in both: Elastic (Young's) Modulus 99 GPa14.4 Msi · Shear Modulus 36 GPa5.2 Msi · Yield Strength (0.2% offset) 300 MPa43.5 ksi · Shear Strength 300 MPa43.5 ksi

Physical

Density and transition temperatures.

Density

6.57 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

1,855°C3,371 °F
1,845°C3,353 °F

Thermal

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

Thermal Conductivity

14.6 W/m·K8.4 BTU/hr·ft·°F
13 W/m·K7.5 BTU/hr·ft·°F

Latent Heat of Fusion

210 J/g90.3 BTU/lb
155 J/g66.6 BTU/lb

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 · Thermal Expansion (CTE, 20–100 °C) 6 µm/m·K3.3 µin/in·°F · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

3.4 % IACS
2.5 % IACS

Electrical Resistivity

5×10⁻⁷ Ω·m19.7 µΩ·in
6.8×10⁻⁷ Ω·m26.8 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.1 V
-0.15 V

Corrosion Resistance

92 / 100
90 / 100

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

25%
28%

Weldability

80 / 100
65 / 100

Formability (cold)

55 / 100
20 / 100

Castability

25 / 100
55 / 100

Same in both: Machinability 30 / 100 · Brazeability / Solderability 20 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

1,400 MJ/kg601,892 BTU/lb
1,200 MJ/kg515,908 BTU/lb

Embodied Carbon (primary production)

95 kg CO₂/kg
75 kg CO₂/kg

Typical Recycled Content

20%
25%

Same in both: Embodied Water 900 L/kg108 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

72 kN·m/kg
69 kN·m/kg

Thermal Diffusivity

7.8 mm²/s
7 mm²/s

Thermal Shock Resistance Index

12
10

Same in both: Specific Stiffness (E / density) 15.1 MN·m/kg · Modulus of Resilience 455 kJ/m³

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 704

Manufacturing and finishing

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

Zr 704 vs Zr 704C — frequently asked

What is the difference between Zr 704 and Zr 704C?

Refractory Metal Zr 704 and Zr 704C are both refractory metal grades. Both yield at about 300 MPa — strength does not separate them. Zr 704 is the more ductile: elongation 22% versus 13% for Zr 704C, and Zr 704C is harder (190 HB vs 180 HB).

Which is cheaper, Zr 704 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 704 or Zr 704C?

Zr 704. Its weldability rates very good (80/100) against good (65/100) for Zr 704C.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Zr 704 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.