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Stainless Steel ER308 vs ER430LNb

Stainless Steel · grade comparison

Stainless Steel ER308 and ER430LNb are both stainless steel grades. ER308 is the stronger of the two: yield strength 400 MPa (58 ksi) against 380 MPa (55.1 ksi) for ER430LNb, about 5% more; tensile strength follows at 600 MPa (87 ksi) vs 520 MPa (75.4 ksi). ER308 is the more ductile: elongation 40% versus 24% for ER430LNb. ER430LNb conducts heat better (25 W/m·K vs 15.5 W/m·K). On the shop floor, ER430LNb machines more easily (50 vs 38 out of 100) and ER308 welds better (excellent vs very good).

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

ER430LNbChoose it when the part is machined in volume.

ER308 vs ER430LNb: properties

ER308ER430LNb

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

195 GPa28.3 Msi
200 GPa29 Msi

Bulk Modulus

145 GPa21 Msi
160 GPa23.2 Msi

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

600 MPa87 ksi
520 MPa75.4 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
380 MPa55.1 ksi

Elongation at Break

40%
24%

Reduction in Area

55%
45%

Compressive Strength

400 MPa58 ksi
385 MPa55.8 ksi

Shear Strength

400 MPa58 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
230 MPa33.4 ksi

Fracture Toughness (K_IC)

150 MPa·√m137 ksi·√in
50 MPa·√m45.5 ksi·√in

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
25 J18.4 ft·lbf

Hardness, Rockwell C

—
10 HRC

Same in both: Shear Modulus 77 GPa11.2 Msi · Hardness, Brinell 185 HB · Hardness, Rockwell B 90 HRB · Hardness, Vickers 195 HV

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,400°C2,552 °F
1,425°C2,597 °F

Liquidus Temperature

1,450°C2,642 °F
1,510°C2,750 °F

Thermal

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

Thermal Conductivity

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

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

Max Service Temperature (continuous)

760°C1,400 °F
815°C1,499 °F

Min Service Temperature

-196°C-321 °F
-20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.4 % IACS
2.9 % IACS

Electrical Resistivity

7.4×10⁻⁷ Ω·m29.1 µΩ·in
6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.08 V
-0.15 V

Corrosion Resistance

65 / 100
48 / 100

Manufacturability

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

Machinability

38 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
55%

Weldability

95 / 100
80 / 100

Polishability

70 / 100
65 / 100

Same in both: Formability (cold) 55 / 100 · Brazeability / Solderability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

57 MJ/kg24,506 BTU/lb
50 MJ/kg21,496 BTU/lb

Embodied Carbon (primary production)

5 kg CO₂/kg
3.6 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
180 L/kg21.6 gal/lb

Typical Recycled Content

45%
65%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

76 kN·m/kg
68 kN·m/kg

Specific Stiffness (E / density)

24.7 MN·m/kg
26 MN·m/kg

Modulus of Resilience

410 kJ/m³
361 kJ/m³

Thermal Diffusivity

3.9 mm²/s
7.1 mm²/s

Thermal Shock Resistance Index

3
6

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 scaleER308ER430LNb

Manufacturing and finishing

CapabilityER308ER430LNb
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.

ER308 vs ER430LNb — frequently asked

Is ER308 stronger than ER430LNb?

Yes. ER308 has a typical yield strength of 400 MPa (58 ksi) against 380 MPa (55.1 ksi) for ER430LNb — about 5% more. Tensile strength is 600 MPa (87 ksi) vs 520 MPa (75.4 ksi).

Which is cheaper, ER308 or ER430LNb?

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, ER308 or ER430LNb?

ER430LNb, by a small margin. Both rate fair for machinability — 50/100 against 38/100 for ER308; for welding the order is ER308 first (excellent, 95/100) then ER430LNb (very good, 80/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER308 and ER430LNb 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.