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Refractory Metal E635 vs Zr 702C

Refractory Metal · grade comparison

Refractory Metal E635 and Zr 702C are both refractory metal grades. E635 is the stronger of the two: yield strength 340 MPa (49.3 ksi) against 250 MPa (36.3 ksi) for Zr 702C, about 36% more. E635 is the more ductile: elongation 22% versus 16% for Zr 702C, and E635 is harder (185 HB vs 150 HB). Zr 702C conducts heat better (22 W/m·K vs 14.5 W/m·K).

E635Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

E635 vs Zr 702C: properties

E635Zr 702C

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

97 GPa14.1 Msi
99 GPa14.4 Msi

Bulk Modulus

100 GPa14.5 Msi
90 GPa13.1 Msi

Poisson's Ratio

0.35
0.34

Tensile Strength (Ultimate)

470 MPa68.2 ksi
450 MPa65.3 ksi

Yield Strength (0.2% offset)

340 MPa49.3 ksi
250 MPa36.3 ksi

Elongation at Break

22%
16%

Reduction in Area

48%
25%

Compressive Strength

350 MPa50.8 ksi
—

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
160 MPa23.2 ksi

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

185 HB
150 HB

Hardness, Rockwell B

89 HRB
88 HRB

Hardness, Vickers

195 HV
—

Same in both: Shear Modulus 36 GPa5.2 Msi · Shear Strength 290 MPa42.1 ksi · Fracture Toughness (K_IC) 55 MPa·√m50.1 ksi·√in

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,760°C3,200 °F
1,852°C3,366 °F

Liquidus Temperature

1,830°C3,326 °F
1,855°C3,371 °F

Thermal

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

Thermal Conductivity

14.5 W/m·K8.4 BTU/hr·ft·°F
22 W/m·K12.7 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

235 J/g101 BTU/lb
155 J/g66.6 BTU/lb

Same in both: Specific Heat Capacity 285 J/kg·K0.07 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.6 % IACS
4.3 % IACS

Electrical Resistivity

6.7×10⁻⁷ Ω·m26.4 µΩ·in
4×10⁻⁷ Ω·m15.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.3 V
-0.25 V

Corrosion Resistance

86 / 100
92 / 100

Manufacturability

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

Machinability

30 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

25%
32%

Weldability

70 / 100
75 / 100

Formability (cold)

60 / 100
20 / 100

Castability

20 / 100
55 / 100

Polishability

60 / 100
65 / 100

Same in both: Brazeability / Solderability 25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

1,400 MJ/kg601,892 BTU/lb
1,250 MJ/kg537,404 BTU/lb

Embodied Carbon (primary production)

90 kg CO₂/kg
80 kg CO₂/kg

Typical Recycled Content

10%
25%

Same in both: Embodied Water 600 L/kg71.9 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

72 kN·m/kg
69 kN·m/kg

Specific Stiffness (E / density)

14.8 MN·m/kg
15.2 MN·m/kg

Modulus of Resilience

596 kJ/m³
316 kJ/m³

Thermal Diffusivity

7.7 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

12
17

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 702CE635

Manufacturing and finishing

CapabilityE635Zr 702C
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

E635 vs Zr 702C — frequently asked

Is E635 stronger than Zr 702C?

Yes. E635 has a typical yield strength of 340 MPa (49.3 ksi) against 250 MPa (36.3 ksi) for Zr 702C — about 36% more. Tensile strength is 470 MPa (68.2 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, E635 or Zr 702C?

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, E635 or Zr 702C?

Zr 702C. Its machinability rates fair (35/100) against poor (30/100) for E635; for welding the order is Zr 702C first (very good, 75/100) then E635 (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E635 and Zr 702C 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.