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Refractory Metal I-220H vs I-70-H

Refractory Metal · grade comparison

Refractory Metal I-220H and I-70-H are both refractory metal grades. I-220H is the stronger of the two: yield strength 345 MPa (50 ksi) against 205 MPa (29.7 ksi) for I-70-H, about 68% more; tensile strength follows at 462 MPa (67 ksi) vs 310 MPa (45 ksi). In exchange, I-70-H is the more ductile: elongation 4.5% versus 2% for I-220H, and I-220H is harder (180 HB vs 120 HB). On the shop floor, I-70-H machines more easily (fair vs poor).

I-220HChoose it when strength drives the design.

I-70-HChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

I-220H vs I-70-H: properties

I-220HI-70-H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

138 GPa20 Msi
145 GPa21 Msi

Bulk Modulus

117 GPa17 Msi
116 GPa16.8 Msi

Poisson's Ratio

0.07
0.08

Tensile Strength (Ultimate)

462 MPa67 ksi
310 MPa45 ksi

Yield Strength (0.2% offset)

345 MPa50 ksi
205 MPa29.7 ksi

Elongation at Break

2%
4.5%

Reduction in Area

2%
5%

Compressive Strength

450 MPa65.3 ksi
250 MPa36.3 ksi

Shear Strength

225 MPa32.6 ksi
200 MPa29 ksi

Fatigue Strength (Endurance Limit)

205 MPa29.7 ksi
140 MPa20.3 ksi

Fracture Toughness (K_IC)

10 MPa·√m9.1 ksi·√in
12 MPa·√m10.9 ksi·√in

Hardness, Brinell

180 HB
120 HB

Hardness, Rockwell B

88 HRB
70 HRB

Hardness, Vickers

190 HV
130 HV

Same in both: Elastic (Young's) Modulus 303 GPa43.9 Msi · Charpy V-Notch Impact (RT) 2 J1.1 ft·lbf

Physical

Density and transition temperatures.

Same in both: Density 1.85 g/cm³0.07 lb/in³ · Melting Point (Solidus) 1,287°C2,349 °F · Liquidus Temperature 1,289°C2,352 °F

Thermal

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

Thermal Conductivity

190 W/m·K110 BTU/hr·ft·°F
210 W/m·K121 BTU/hr·ft·°F

Specific Heat Capacity

1,900 J/kg·K0.45 BTU/lb·°F
1,925 J/kg·K0.46 BTU/lb·°F

Min Service Temperature

-200°C-328 °F
-195°C-319 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 11.3 µm/m·K6.3 µin/in·°F · Latent Heat of Fusion 1,355 J/g583 BTU/lb · Max Service Temperature (continuous) 500°C932 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

40 % IACS
41 % IACS

Electrical Resistivity

4.3×10⁻⁸ Ω·m1.69 µΩ·in
4.2×10⁻⁸ Ω·m1.65 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-1 V
-0.98 V

Same in both: Corrosion Resistance 45 / 100

Manufacturability

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

Machinability

25 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

25%
45%

Formability (cold)

5 / 100
8 / 100

Brazeability / Solderability

45 / 100
55 / 100

Polishability

55 / 100
50 / 100

Castability

—
15 / 100

Same in both: Weldability 20 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

3,500 MJ/kg1,504,731 BTU/lb
1,600 MJ/kg687,877 BTU/lb

Embodied Carbon (primary production)

210 kg CO₂/kg
105 kg CO₂/kg

Embodied Water

1,500 L/kg180 gal/lb
1,800 L/kg216 gal/lb

Typical Recycled Content

15%
10%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

250 kN·m/kg
168 kN·m/kg

Modulus of Resilience

196 kJ/m³
69 kJ/m³

Thermal Diffusivity

54.1 mm²/s
59 mm²/s

Thermal Shock Resistance Index

26
19

Same in both: Specific Stiffness (E / density) 163.8 MN·m/kg

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 scaleI-70-HI-220H

Manufacturing and finishing

CapabilityI-220HI-70-H
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

I-220H vs I-70-H — frequently asked

Is I-220H stronger than I-70-H?

Yes. I-220H has a typical yield strength of 345 MPa (50 ksi) against 205 MPa (29.7 ksi) for I-70-H — about 68% more. Tensile strength is 462 MPa (67 ksi) vs 310 MPa (45 ksi).

Which is cheaper, I-220H or I-70-H?

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, I-220H or I-70-H?

I-70-H. Its machinability rates fair (35/100) against poor (25/100) for I-220H.

Ready to make it?

Upload a CAD file and FabDigit prices the part in I-220H and I-70-H 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.