Stainless Steel ER308Si vs ER330
Stainless Steel · grade comparison
Stainless Steel ER308Si and ER330 are both stainless steel grades. ER308Si is the stronger of the two: yield strength 400 MPa (58 ksi) against 380 MPa (55.1 ksi) for ER330, about 5% more; tensile strength follows at 600 MPa (87 ksi) vs 570 MPa (82.7 ksi). ER308Si is the more ductile: elongation 38% versus 31% for ER330, and ER330 is harder (190 HB vs 175 HB). ER330 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, $$$) than ER330 (high, $$$$).
ER308SiChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
ER330Choose it when the part sees heat.
ER308Si vs ER330: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all stainless steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Poisson's Ratio 0.29 · Shear Strength 400 MPa58 ksi · Fatigue Strength (Endurance Limit) 240 MPa34.8 ksi
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | ER308Si | ER330 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$ Premium | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.
ER308Si vs ER330 — frequently asked
Is ER308Si stronger than ER330?
Yes. ER308Si has a typical yield strength of 400 MPa (58 ksi) against 380 MPa (55.1 ksi) for ER330 — about 5% more. Tensile strength is 600 MPa (87 ksi) vs 570 MPa (82.7 ksi).
Which is cheaper, ER308Si or ER330?
ER308Si is the lower-cost material: it sits in the premium tier ($$$) while ER330 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, ER308Si or ER330?
ER308Si. Its machinability rates fair (40/100) against poor (25/100) for ER330; for welding the order is ER308Si first (excellent, 95/100) then ER330 (good, 60/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in ER308Si and ER330 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.