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Stainless Steel ER308 vs ER430

Stainless Steel · grade comparison

Stainless Steel ER308 and ER430 are both stainless steel grades. ER308 is the stronger of the two: tensile strength 600 MPa (87 ksi) against 520 MPa (75.4 ksi) for ER430, about 15% more. ER308 is the more ductile: elongation 40% versus 18% for ER430, and ER430 is harder (200 HB vs 185 HB). ER430 conducts heat better (23.9 W/m·K vs 15.5 W/m·K). On the shop floor, ER430 machines more easily (good vs fair) and ER308 welds better (excellent vs good).

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

ER430Choose it when the part is machined in volume.

ER308 vs ER430: properties

ER308ER430

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
0.28

Tensile Strength (Ultimate)

600 MPa87 ksi
520 MPa75.4 ksi

Elongation at Break

40%
18%

Reduction in Area

55%
40%

Compressive Strength

400 MPa58 ksi
—

Shear Strength

400 MPa58 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
230 MPa33.4 ksi

Fracture Toughness (K_IC)

150 MPa·√m137 ksi·√in
—

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
20 J14.8 ft·lbf

Hardness, Brinell

185 HB
200 HB

Hardness, Rockwell B

90 HRB
93 HRB

Hardness, Vickers

195 HV
210 HV

Same in both: Shear Modulus 77 GPa11.2 Msi · Yield Strength (0.2% offset) 400 MPa58 ksi

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
23.9 W/m·K13.8 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

Min Service Temperature

-196°C-321 °F
-20°C-4 °F

Same in both: Max Service Temperature (continuous) 760°C1,400 °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
-0.2 V

Corrosion Resistance

65 / 100
42 / 100

Manufacturability

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

Machinability

38 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
50%

Weldability

95 / 100
55 / 100

Formability (cold)

55 / 100
45 / 100

Polishability

70 / 100
80 / 100

Same in both: Brazeability / Solderability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

57 MJ/kg24,506 BTU/lb
45 MJ/kg19,347 BTU/lb

Embodied Carbon (primary production)

5 kg CO₂/kg
3.4 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

45%
60%

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
400 kJ/m³

Thermal Diffusivity

3.9 mm²/s
6.7 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 scaleER308ER430

Manufacturing and finishing

CapabilityER308ER430
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 ER430 — frequently asked

Is ER308 stronger than ER430?

Yes. ER308 has a typical tensile strength of 600 MPa (87 ksi) against 520 MPa (75.4 ksi) for ER430 — about 15% more.

Which is cheaper, ER308 or ER430?

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 ER430?

ER430. Its machinability rates good (55/100) against fair (38/100) for ER308; for welding the order is ER308 first (excellent, 95/100) then ER430 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER308 and ER430 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.