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Refractory Metal Zr 702 vs Zr 706

Refractory Metal · grade comparison

Refractory Metal Zr 702 and Zr 706 are both refractory metal grades. Zr 706 is the stronger of the two: yield strength 400 MPa (58 ksi) against 290 MPa (42.1 ksi) for Zr 702, about 38% more; tensile strength follows at 550 MPa (79.8 ksi) vs 450 MPa (65.3 ksi). In exchange, Zr 702 is the more ductile: elongation 30% versus 24% for Zr 706, and Zr 706 is harder (180 HB vs 150 HB). Zr 702 conducts heat better (22 W/m·K vs 17.1 W/m·K).

Zr 702Choose it when the part is bent, formed or impact-loaded.

Zr 706Choose it when strength drives the design.

Zr 702 vs Zr 706: properties

Zr 702Zr 706

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

99 GPa14.4 Msi
97 GPa14.1 Msi

Tensile Strength (Ultimate)

450 MPa65.3 ksi
550 MPa79.8 ksi

Yield Strength (0.2% offset)

290 MPa42.1 ksi
400 MPa58 ksi

Elongation at Break

30%
24%

Reduction in Area

45%
40%

Compressive Strength

300 MPa43.5 ksi
420 MPa60.9 ksi

Shear Strength

290 MPa42.1 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

65 MPa·√m59.2 ksi·√in
60 MPa·√m54.6 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

150 HB
180 HB

Hardness, Rockwell B

85 HRB
88 HRB

Hardness, Vickers

160 HV
190 HV

Same in both: Shear Modulus 36 GPa5.2 Msi · Bulk Modulus 92 GPa13.3 Msi · Poisson's Ratio 0.35

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)

5.9 µm/m·K3.3 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)

371°C700 °F
400°C752 °F

Same in both: Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

4.3 % IACS
3.1 % IACS

Electrical Resistivity

4×10⁻⁷ Ω·m15.7 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)

-0.2 V
-0.15 V

Corrosion Resistance

92 / 100
88 / 100

Manufacturability

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

Machinability

35 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
40%

Weldability

80 / 100
75 / 100

Formability (cold)

70 / 100
62 / 100

Castability

30 / 100
25 / 100

Brazeability / Solderability

25 / 100
20 / 100

Polishability

70 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

1,250 MJ/kg537,404 BTU/lb
1,300 MJ/kg558,900 BTU/lb

Embodied Carbon (primary production)

85 kg CO₂/kg
78 kg CO₂/kg

Embodied Water

900 L/kg108 gal/lb
500 L/kg59.9 gal/lb

Typical Recycled Content

15%
20%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

69 kN·m/kg
83 kN·m/kg

Specific Stiffness (E / density)

15.2 MN·m/kg
14.6 MN·m/kg

Modulus of Resilience

425 kJ/m³
825 kJ/m³

Thermal Diffusivity

11.9 mm²/s
9.2 mm²/s

Thermal Shock Resistance Index

17
16

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 702Zr 706

Manufacturing and finishing

CapabilityZr 702Zr 706
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Zr 702 vs Zr 706 — frequently asked

Is Zr 706 stronger than Zr 702?

Yes. Zr 706 has a typical yield strength of 400 MPa (58 ksi) against 290 MPa (42.1 ksi) for Zr 702 — about 38% more. Tensile strength is 550 MPa (79.8 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, Zr 702 or Zr 706?

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, Zr 702 or Zr 706?

Zr 706, by a small margin. Both rate fair for machinability — 40/100 against 35/100 for Zr 702; for welding the order is Zr 702 first (very good, 80/100) then Zr 706 (very good, 75/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Zr 702 and Zr 706 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.