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Refractory Metal Reactor Grade Zr vs Zr 704C

Refractory Metal · grade comparison

Refractory Metal Reactor Grade Zr and Zr 704C are both refractory metal grades. Zr 704C is the stronger of the two: yield strength 300 MPa (43.5 ksi) against 200 MPa (29 ksi) for Reactor Grade Zr, about 50% more; tensile strength follows at 450 MPa (65.3 ksi) vs 330 MPa (47.9 ksi). In exchange, Reactor Grade Zr is the more ductile: elongation 30% versus 13% for Zr 704C, and Zr 704C is harder (190 HB vs 95 HB). Zr 704C runs hotter in service (400°C vs 350°C continuous) and Reactor Grade Zr conducts heat better (22 W/m·K vs 13 W/m·K). On the shop floor, Reactor Grade Zr welds better (very good vs good).

Reactor Grade ZrChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

Zr 704CChoose it when strength drives the design, or when the part sees heat.

Reactor Grade Zr vs Zr 704C: properties

Reactor Grade ZrZr 704C

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

91 GPa13.2 Msi
97 GPa14.1 Msi

Tensile Strength (Ultimate)

330 MPa47.9 ksi
450 MPa65.3 ksi

Yield Strength (0.2% offset)

200 MPa29 ksi
300 MPa43.5 ksi

Elongation at Break

30%
13%

Reduction in Area

45%
20%

Compressive Strength

220 MPa31.9 ksi
320 MPa46.4 ksi

Shear Strength

215 MPa31.2 ksi
300 MPa43.5 ksi

Fatigue Strength (Endurance Limit)

180 MPa26.1 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)

70 J51.6 ft·lbf
20 J14.8 ft·lbf

Hardness, Brinell

95 HB
190 HB

Hardness, Rockwell B

50 HRB
89 HRB

Hardness, Vickers

100 HV
200 HV

Same in both: Elastic (Young's) Modulus 99 GPa14.4 Msi · Shear Modulus 36 GPa5.2 Msi · Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,852°C3,366 °F
1,800°C3,272 °F

Liquidus Temperature

1,852°C3,366 °F
1,845°C3,353 °F

Thermal

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

Thermal Conductivity

22 W/m·K12.7 BTU/hr·ft·°F
13 W/m·K7.5 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

5.8 µm/m·K3.2 µin/in·°F
6 µm/m·K3.3 µin/in·°F

Latent Heat of Fusion

153 J/g65.8 BTU/lb
155 J/g66.6 BTU/lb

Max Service Temperature (continuous)

350°C662 °F
400°C752 °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

Electrical

Conductivity and insulation.

Electrical Conductivity

4.1 % IACS
2.5 % IACS

Electrical Resistivity

4.2×10⁻⁷ Ω·m16.5 µΩ·in
6.8×10⁻⁷ Ω·m26.8 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

88 / 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

35 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

25%
28%

Weldability

80 / 100
65 / 100

Formability (cold)

75 / 100
20 / 100

Castability

25 / 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

Typical Recycled Content

5%
25%

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

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

51 kN·m/kg
69 kN·m/kg

Specific Stiffness (E / density)

15.2 MN·m/kg
15.1 MN·m/kg

Modulus of Resilience

202 kJ/m³
455 kJ/m³

Thermal Diffusivity

11.9 mm²/s
7 mm²/s

Thermal Shock Resistance Index

13
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 704CReactor Grade Zr

Manufacturing and finishing

CapabilityReactor Grade ZrZr 704C
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Reactor Grade Zr vs Zr 704C — frequently asked

Is Zr 704C stronger than Reactor Grade Zr?

Yes. Zr 704C has a typical yield strength of 300 MPa (43.5 ksi) against 200 MPa (29 ksi) for Reactor Grade Zr — about 50% more. Tensile strength is 450 MPa (65.3 ksi) vs 330 MPa (47.9 ksi).

Which is cheaper, Reactor Grade Zr 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 is easier to machine, Reactor Grade Zr or Zr 704C?

Reactor Grade Zr. Its machinability rates fair (35/100) against poor (30/100) for Zr 704C; for welding the order is Reactor Grade Zr first (very good, 80/100) then Zr 704C (good, 65/100).

Ready to make it?

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