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Stainless Steel E310Nb vs ER308Si

Stainless Steel · grade comparison

Stainless Steel E310Nb and ER308Si are both stainless steel grades. Both yield at about 420 MPa — strength does not separate them. ER308Si is the more ductile: elongation 38% versus 32% for E310Nb. E310Nb runs hotter in service (1,050°C vs 760°C continuous). On the shop floor, ER308Si machines more easily (fair vs poor), ER308Si welds better (excellent vs very good), and ER308Si sits in a lower cost tier (premium, $$$) than E310Nb (high, $$$$).

E310NbChoose it when the part sees heat.

ER308SiChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

E310Nb vs ER308Si: properties

E310NbER308Si

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
195 GPa28.3 Msi

Poisson's Ratio

0.28
0.29

Yield Strength (0.2% offset)

420 MPa60.9 ksi
400 MPa58 ksi

Elongation at Break

32%
38%

Reduction in Area

45%
55%

Compressive Strength

430 MPa62.4 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
140 MPa·√m127 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

180 HB
175 HB

Hardness, Rockwell C

9 HRC
—

Hardness, Vickers

190 HV
185 HV

Same in both: Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Tensile Strength (Ultimate) 600 MPa87 ksi · Shear Strength 400 MPa58 ksi · Hardness, Rockwell B 88 HRB

Physical

Density and transition temperatures.

Density

7.9 g/cm³0.29 lb/in³
7.95 g/cm³0.29 lb/in³

Same in both: Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °F

Thermal

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

Thermal Conductivity

14.2 W/m·K8.2 BTU/hr·ft·°F
15 W/m·K8.7 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

15.5 µm/m·K8.6 µin/in·°F
16.5 µm/m·K9.2 µin/in·°F

Max Service Temperature (continuous)

1,050°C1,922 °F
760°C1,400 °F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.2 % IACS
2.4 % IACS

Electrical Resistivity

7.8×10⁻⁷ Ω·m30.7 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)

-0.1 V
-0.08 V

Corrosion Resistance

66 / 100
68 / 100

Manufacturability

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

Machinability

28 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
45%

Weldability

72 / 100
95 / 100

Formability (cold)

45 / 100
60 / 100

Brazeability / Solderability

55 / 100
60 / 100

Polishability

65 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

62 MJ/kg26,655 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

6 kg CO₂/kg
5.5 kg CO₂/kg

Embodied Water

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

Same in both: Typical Recycled Content 55%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

76 kN·m/kg
75 kN·m/kg

Specific Stiffness (E / density)

25.3 MN·m/kg
24.5 MN·m/kg

Modulus of Resilience

441 kJ/m³
410 kJ/m³

Thermal Diffusivity

3.6 mm²/s
3.8 mm²/s

Same in both: Thermal Shock Resistance Index 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 scaleER308SiE310Nb

Manufacturing and finishing

CapabilityE310NbER308Si
Default condition——
Relative cost$$$$ High$$$ 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.

E310Nb vs ER308Si — frequently asked

What is the difference between E310Nb and ER308Si?

Stainless Steel E310Nb and ER308Si are both stainless steel grades. Both yield at about 420 MPa — strength does not separate them. ER308Si is the more ductile: elongation 38% versus 32% for E310Nb.

Which is cheaper, E310Nb or ER308Si?

ER308Si is the lower-cost material: it sits in the premium tier ($$$) while E310Nb is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, E310Nb or ER308Si?

ER308Si. Its machinability rates fair (40/100) against poor (28/100) for E310Nb; for welding the order is ER308Si first (excellent, 95/100) then E310Nb (very good, 72/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E310Nb 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.