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Stainless Steel E430 vs ER308Si

Stainless Steel · grade comparison

Stainless Steel E430 and ER308Si are both stainless steel grades. ER308Si is the stronger of the two: tensile strength 600 MPa (87 ksi) against 520 MPa (75.4 ksi) for E430, about 15% more. ER308Si is the more ductile: elongation 38% versus 22% for E430, and E430 is harder (185 HB vs 175 HB). E430 is lighter (7.7 g/cm³ vs 7.95 g/cm³ for ER308Si) and E430 conducts heat better (23.9 W/m·K vs 15 W/m·K). On the shop floor, ER308Si welds better (excellent vs good).

E430Choose it when weight is the constraint.

ER308SiChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

E430 vs ER308Si: properties

E430ER308Si

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
195 GPa28.3 Msi

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

520 MPa75.4 ksi
600 MPa87 ksi

Elongation at Break

22%
38%

Reduction in Area

45%
55%

Compressive Strength

410 MPa59.5 ksi
400 MPa58 ksi

Shear Strength

320 MPa46.4 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

48 MPa·√m43.7 ksi·√in
140 MPa·√m127 ksi·√in

Charpy V-Notch Impact (RT)

15 J11.1 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

185 HB
175 HB

Hardness, Rockwell B

90 HRB
88 HRB

Hardness, Vickers

195 HV
185 HV

Same in both: Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Yield Strength (0.2% offset) 400 MPa58 ksi

Physical

Density and transition temperatures.

Density

7.7 g/cm³0.28 lb/in³
7.95 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

23.9 W/m·K13.8 BTU/hr·ft·°F
15 W/m·K8.7 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
16.5 µm/m·K9.2 µin/in·°F

Latent Heat of Fusion

275 J/g118 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

800°C1,472 °F
760°C1,400 °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)

-0.3 V
-0.08 V

Corrosion Resistance

45 / 100
68 / 100

Manufacturability

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

Machinability

45 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

54%
45%

Weldability

55 / 100
95 / 100

Formability (cold)

30 / 100
60 / 100

Brazeability / Solderability

55 / 100
60 / 100

Same in both: Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

38 MJ/kg16,337 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

3 kg CO₂/kg
5.5 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
200 L/kg24 gal/lb

Typical Recycled Content

65%
55%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

68 kN·m/kg
75 kN·m/kg

Specific Stiffness (E / density)

26 MN·m/kg
24.5 MN·m/kg

Modulus of Resilience

400 kJ/m³
410 kJ/m³

Thermal Diffusivity

6.7 mm²/s
3.8 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 scaleER308SiE430

Manufacturing and finishing

CapabilityE430ER308Si
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.

E430 vs ER308Si — frequently asked

Is ER308Si stronger than E430?

Yes. ER308Si has a typical tensile strength of 600 MPa (87 ksi) against 520 MPa (75.4 ksi) for E430 — about 15% more.

Which is cheaper, E430 or ER308Si?

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, E430 or ER308Si?

E430, by a small margin. Both rate fair for machinability — 45/100 against 40/100 for ER308Si; for welding the order is ER308Si first (excellent, 95/100) then E430 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E430 and ER308Si 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.