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Stainless Steel E409Nb vs ER308H

Stainless Steel · grade comparison

Stainless Steel E409Nb and ER308H are both stainless steel grades. ER308H is the stronger of the two: yield strength 415 MPa (60.2 ksi) against 380 MPa (55.1 ksi) for E409Nb, about 9% more; tensile strength follows at 590 MPa (85.6 ksi) vs 500 MPa (72.5 ksi). ER308H is the more ductile: elongation 38% versus 22% for E409Nb. ER308H runs hotter in service (800°C vs 675°C continuous) and E409Nb conducts heat better (25 W/m·K vs 16.2 W/m·K). On the shop floor, E409Nb machines more easily (48 vs 38 out of 100) and ER308H welds better (excellent vs very good).

E409NbChoose it when the part is machined in volume.

ER308HChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

E409Nb vs ER308H: properties

E409NbER308H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
196 GPa28.4 Msi

Poisson's Ratio

0.28
0.29

Tensile Strength (Ultimate)

500 MPa72.5 ksi
590 MPa85.6 ksi

Yield Strength (0.2% offset)

380 MPa55.1 ksi
415 MPa60.2 ksi

Elongation at Break

22%
38%

Reduction in Area

50%
55%

Compressive Strength

385 MPa55.8 ksi
420 MPa60.9 ksi

Shear Strength

330 MPa47.9 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

220 MPa31.9 ksi
230 MPa33.4 ksi

Fracture Toughness (K_IC)

40 MPa·√m36.4 ksi·√in
180 MPa·√m164 ksi·√in

Charpy V-Notch Impact (RT)

18 J13.3 ft·lbf
85 J62.7 ft·lbf

Hardness, Brinell

180 HB
175 HB

Hardness, Rockwell B

88 HRB
87 HRB

Hardness, Vickers

190 HV
185 HV

Same in both: Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Density

7.7 g/cm³0.28 lb/in³
7.9 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,480°C2,696 °F
1,400°C2,552 °F

Liquidus Temperature

1,530°C2,786 °F
1,450°C2,642 °F

Thermal

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

Thermal Conductivity

25 W/m·K14.4 BTU/hr·ft·°F
16.2 W/m·K9.4 BTU/hr·ft·°F

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
500 J/kg·K0.12 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11 µm/m·K6.1 µin/in·°F
16.5 µm/m·K9.2 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
285 J/g123 BTU/lb

Max Service Temperature (continuous)

675°C1,247 °F
800°C1,472 °F

Min Service Temperature

-20°C-4 °F
-196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.9 % IACS
2.4 % IACS

Electrical Resistivity

6×10⁻⁷ Ω·m23.6 µΩ·in
7.2×10⁻⁷ Ω·m28.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.25 V
-0.05 V

Corrosion Resistance

45 / 100
58 / 100

Manufacturability

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

Machinability

48 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
40%

Weldability

70 / 100
88 / 100

Formability (cold)

35 / 100
55 / 100

Brazeability / Solderability

45 / 100
60 / 100

Polishability

55 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

52 MJ/kg22,356 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

3.8 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

65%
60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

65 kN·m/kg
75 kN·m/kg

Specific Stiffness (E / density)

26 MN·m/kg
24.8 MN·m/kg

Modulus of Resilience

361 kJ/m³
439 kJ/m³

Thermal Diffusivity

7.1 mm²/s
4.1 mm²/s

Thermal Shock Resistance Index

6
3

Strength versus weight

Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scaleER308HE409Nb

Manufacturing and finishing

CapabilityE409NbER308H
Default condition——
Relative cost$$$ Premium$$$ Premium
Min. machined wall——
Best machined surface——

Both take the same 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.

E409Nb vs ER308H — frequently asked

Is ER308H stronger than E409Nb?

Yes. ER308H has a typical yield strength of 415 MPa (60.2 ksi) against 380 MPa (55.1 ksi) for E409Nb — about 9% more. Tensile strength is 590 MPa (85.6 ksi) vs 500 MPa (72.5 ksi).

Which is cheaper, E409Nb or ER308H?

Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, E409Nb or ER308H?

E409Nb, by a small margin. Both rate fair for machinability — 48/100 against 38/100 for ER308H; for welding the order is ER308H first (excellent, 88/100) then E409Nb (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E409Nb and ER308H 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.