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Refractory Metal Reactor Grade Zr vs Zr 705C

Refractory Metal · grade comparison

Refractory Metal Reactor Grade Zr and Zr 705C are both refractory metal grades. Zr 705C is the stronger of the two: yield strength 386 MPa (56 ksi) against 200 MPa (29 ksi) for Reactor Grade Zr, about 93% more; tensile strength follows at 495 MPa (71.8 ksi) vs 330 MPa (47.9 ksi). In exchange, Reactor Grade Zr is the more ductile: elongation 30% versus 13% for Zr 705C, and Zr 705C is harder (190 HB vs 95 HB). Reactor Grade Zr conducts heat better (22 W/m·K vs 17.1 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 705CChoose it when strength drives the design.

Reactor Grade Zr vs Zr 705C: properties

Reactor Grade ZrZr 705C

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

99 GPa14.4 Msi
97 GPa14.1 Msi

Bulk Modulus

91 GPa13.2 Msi
95 GPa13.8 Msi

Poisson's Ratio

0.34
0.35

Tensile Strength (Ultimate)

330 MPa47.9 ksi
495 MPa71.8 ksi

Yield Strength (0.2% offset)

200 MPa29 ksi
386 MPa56 ksi

Elongation at Break

30%
13%

Reduction in Area

45%
24%

Compressive Strength

220 MPa31.9 ksi
400 MPa58 ksi

Shear Strength

215 MPa31.2 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

180 MPa26.1 ksi
210 MPa30.5 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
40 MPa·√m36.4 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
14 J10.3 ft·lbf

Hardness, Brinell

95 HB
190 HB

Hardness, Rockwell B

50 HRB
92 HRB

Hardness, Vickers

100 HV
200 HV

Hardness, Rockwell C

—
13 HRC

Same in both: Shear Modulus 36 GPa5.2 Msi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,852°C3,366 °F
1,840°C3,344 °F

Liquidus Temperature

1,852°C3,366 °F
1,860°C3,380 °F

Thermal

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

Thermal Conductivity

22 W/m·K12.7 BTU/hr·ft·°F
17.1 W/m·K9.9 BTU/hr·ft·°F

Specific Heat Capacity

285 J/kg·K0.07 BTU/lb·°F
281 J/kg·K0.07 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

5.8 µm/m·K3.2 µin/in·°F
6.3 µm/m·K3.5 µin/in·°F

Max Service Temperature (continuous)

350°C662 °F
375°C707 °F

Min Service Temperature

-196°C-321 °F
-50°C-58 °F

Same in both: Latent Heat of Fusion 153 J/g65.8 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

4.1 % IACS
3.1 % IACS

Electrical Resistivity

4.2×10⁻⁷ Ω·m16.5 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.15 V
-0.25 V

Corrosion Resistance

88 / 100
90 / 100

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%
22%

Weldability

80 / 100
62 / 100

Formability (cold)

75 / 100
12 / 100

Castability

25 / 100
55 / 100

Polishability

60 / 100
70 / 100

Same in both: Brazeability / Solderability 25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

1,300 MJ/kg558,900 BTU/lb
1,600 MJ/kg687,877 BTU/lb

Embodied Carbon (primary production)

80 kg CO₂/kg
105 kg CO₂/kg

Embodied Water

900 L/kg108 gal/lb
600 L/kg71.9 gal/lb

Typical Recycled Content

5%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

51 kN·m/kg
75 kN·m/kg

Specific Stiffness (E / density)

15.2 MN·m/kg
14.6 MN·m/kg

Modulus of Resilience

202 kJ/m³
768 kJ/m³

Thermal Diffusivity

11.9 mm²/s
9.2 mm²/s

Thermal Shock Resistance Index

13
14

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 705CReactor Grade Zr

Manufacturing and finishing

CapabilityReactor Grade ZrZr 705C
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Reactor Grade Zr vs Zr 705C — frequently asked

Is Zr 705C stronger than Reactor Grade Zr?

Yes. Zr 705C has a typical yield strength of 386 MPa (56 ksi) against 200 MPa (29 ksi) for Reactor Grade Zr — about 93% more. Tensile strength is 495 MPa (71.8 ksi) vs 330 MPa (47.9 ksi).

Which is cheaper, Reactor Grade Zr or Zr 705C?

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 705C?

Reactor Grade Zr. Its machinability rates fair (35/100) against poor (30/100) for Zr 705C; for welding the order is Reactor Grade Zr first (very good, 80/100) then Zr 705C (good, 62/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Reactor Grade Zr and Zr 705C 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.