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Stainless Steel E330 vs ER308Si

Stainless Steel · grade comparison

Stainless Steel E330 and ER308Si are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER308Si is the more ductile: elongation 38% versus 32% for E330, and E330 is harder (190 HB vs 175 HB). E330 runs hotter in service (1,100°C vs 760°C continuous) and ER308Si conducts heat better (15 W/m·K vs 12.5 W/m·K). On the shop floor, ER308Si machines more easily (fair vs poor), ER308Si welds better (excellent vs good), and ER308Si sits in a lower cost tier (premium, $$$) than E330 (high, $$$$).

E330Choose 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.

E330 vs ER308Si: properties

E330ER308Si

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

196 GPa28.4 Msi
195 GPa28.3 Msi

Shear Modulus

76 GPa11 Msi
77 GPa11.2 Msi

Elongation at Break

32%
38%

Reduction in Area

35%
55%

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

190 HB
175 HB

Hardness, Rockwell B

90 HRB
88 HRB

Hardness, Vickers

200 HV
185 HV

Fracture Toughness (K_IC)

—
140 MPa·√m127 ksi·√in

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Tensile Strength (Ultimate) 600 MPa87 ksi · Yield Strength (0.2% offset) 400 MPa58 ksi · Compressive Strength 400 MPa58 ksi · Shear Strength 400 MPa58 ksi · Fatigue Strength (Endurance Limit) 240 MPa34.8 ksi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,340°C2,444 °F
1,400°C2,552 °F

Liquidus Temperature

1,400°C2,552 °F
1,450°C2,642 °F

Thermal

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

Thermal Conductivity

12.5 W/m·K7.2 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)

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

Max Service Temperature (continuous)

1,100°C2,012 °F
760°C1,400 °F

Min Service Temperature

-100°C-148 °F
-196°C-321 °F

Latent Heat of Fusion

—
270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

1.7 % IACS
2.4 % IACS

Electrical Resistivity

1.02×10⁻⁶ Ω·m40.2 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)

-0.12 V
-0.08 V

Corrosion Resistance

56 / 100
68 / 100

Manufacturability

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

Machinability

26 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

22%
45%

Weldability

55 / 100
95 / 100

Formability (cold)

38 / 100
60 / 100

Brazeability / Solderability

50 / 100
60 / 100

Polishability

55 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

95 MJ/kg40,843 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

7 kg CO₂/kg
5.5 kg CO₂/kg

Embodied Water

220 L/kg26.4 gal/lb
200 L/kg24 gal/lb

Typical Recycled Content

40%
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)

24.7 MN·m/kg
24.5 MN·m/kg

Modulus of Resilience

408 kJ/m³
410 kJ/m³

Thermal Diffusivity

3.4 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 scaleER308SiE330

Manufacturing and finishing

CapabilityE330ER308Si
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.

E330 vs ER308Si — frequently asked

What is the difference between E330 and ER308Si?

Stainless Steel E330 and ER308Si are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER308Si is the more ductile: elongation 38% versus 32% for E330, and E330 is harder (190 HB vs 175 HB).

Which is cheaper, E330 or ER308Si?

ER308Si is the lower-cost material: it sits in the premium tier ($$$) while E330 is high ($$$$). 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, E330 or ER308Si?

ER308Si. Its machinability rates fair (40/100) against poor (26/100) for E330; for welding the order is ER308Si first (excellent, 95/100) then E330 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E330 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.