Stainless Steel ER308 vs ER308LSi
Stainless Steel · grade comparison
Stainless Steel ER308 and ER308LSi are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER308 is harder — 185 HB against 165 HB for ER308LSi — which matters for wear surfaces and threads. ER308 runs hotter in service (760°C vs 425°C continuous). On the shop floor, ER308LSi forms better (very good vs good).
ER308Choose it when surface hardness matters, or when the part sees heat.
ER308 vs ER308LSi: 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.
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 195 GPa28.3 Msi · Yield Strength (0.2% offset) 400 MPa58 ksi · Reduction in Area 55% · Compressive Strength 400 MPa58 ksi
Physical
Density and transition temperatures.
Same in both: Density 7.9 g/cm³0.29 lb/in³ · 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
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Same in both: Electrical Resistivity 7.4×10⁻⁷ Ω·m29.1 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.08 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Polishability
Same in both: Machinability 38 / 100 · Weldability 95 / 100 · Brazeability / Solderability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 130 L/kg15.6 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Thermal Diffusivity
Same in both: Specific Stiffness (E / density) 24.7 MN·m/kg · Modulus of Resilience 410 kJ/m³ · 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.
Manufacturing and finishing
| Capability | ER308 | ER308LSi |
|---|---|---|
| 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 ER308LSi — frequently asked
What is the difference between ER308 and ER308LSi?
Stainless Steel ER308 and ER308LSi are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER308 is harder — 185 HB against 165 HB for ER308LSi — which matters for wear surfaces and threads.
Which is cheaper, ER308 or ER308LSi?
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.
When should I choose ER308 over ER308LSi?
Pick ER308 when surface hardness matters, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in ER308 and ER308LSi 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.