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Stainless Steel E430Nb vs ER308

Stainless Steel · grade comparison

Stainless Steel E430Nb and ER308 are both stainless steel grades. ER308 is the stronger of the two: tensile strength 600 MPa (87 ksi) against 540 MPa (78.3 ksi) for E430Nb, about 11% more. ER308 is the more ductile: elongation 40% versus 22% for E430Nb, and E430Nb is harder (200 HB vs 185 HB). E430Nb conducts heat better (25 W/m·K vs 15.5 W/m·K). On the shop floor, ER308 welds better (excellent vs good).

ER308Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

E430Nb vs ER308: properties

E430NbER308

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
195 GPa28.3 Msi

Bulk Modulus

160 GPa23.2 Msi
145 GPa21 Msi

Poisson's Ratio

0.28
0.3

Tensile Strength (Ultimate)

540 MPa78.3 ksi
600 MPa87 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
400 MPa58 ksi

Elongation at Break

22%
40%

Reduction in Area

45%
55%

Compressive Strength

425 MPa61.6 ksi
400 MPa58 ksi

Shear Strength

350 MPa50.8 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

35 MPa·√m31.9 ksi·√in
150 MPa·√m137 ksi·√in

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

200 HB
185 HB

Hardness, Rockwell B

93 HRB
90 HRB

Hardness, Rockwell C

14 HRC
—

Hardness, Vickers

210 HV
195 HV

Same in both: Shear Modulus 77 GPa11.2 Msi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,425°C2,597 °F
1,400°C2,552 °F

Liquidus Temperature

1,510°C2,750 °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
15.5 W/m·K9 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)

10.4 µm/m·K5.8 µin/in·°F
16.9 µm/m·K9.4 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
280 J/g120 BTU/lb

Max Service Temperature (continuous)

800°C1,472 °F
760°C1,400 °F

Min Service Temperature

0°C32 °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
7.4×10⁻⁷ Ω·m29.1 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.25 V
-0.08 V

Corrosion Resistance

50 / 100
65 / 100

Manufacturability

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

Machinability

45 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
45%

Weldability

60 / 100
95 / 100

Formability (cold)

30 / 100
55 / 100

Polishability

60 / 100
70 / 100

Brazeability / Solderability

—
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
57 MJ/kg24,506 BTU/lb

Embodied Carbon (primary production)

4.2 kg CO₂/kg
5 kg CO₂/kg

Embodied Water

100 L/kg12 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

55%
45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

70 kN·m/kg
76 kN·m/kg

Specific Stiffness (E / density)

26 MN·m/kg
24.7 MN·m/kg

Modulus of Resilience

441 kJ/m³
410 kJ/m³

Thermal Diffusivity

7.1 mm²/s
3.9 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 scaleER308E430Nb

Manufacturing and finishing

CapabilityE430NbER308
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.

E430Nb vs ER308 — frequently asked

Is ER308 stronger than E430Nb?

Yes. ER308 has a typical tensile strength of 600 MPa (87 ksi) against 540 MPa (78.3 ksi) for E430Nb — about 11% more.

Which is cheaper, E430Nb or ER308?

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, E430Nb or ER308?

E430Nb, by a small margin. Both rate fair for machinability — 45/100 against 38/100 for ER308; for welding the order is ER308 first (excellent, 95/100) then E430Nb (good, 60/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E430Nb and ER308 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.