Stainless Steel ER309LSi vs ER316
Stainless Steel · grade comparison
Stainless Steel ER309LSi and ER316 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER309LSi runs hotter in service (950°C vs 760°C continuous). On the shop floor, ER316 sits in a lower cost tier (premium, $$$) than ER309LSi (high, $$$$).
ER309LSiChoose it when the part sees heat.
ER316Choose it when cost is the deciding factor.
ER309LSi vs ER316: 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
Bulk Modulus
Poisson's Ratio
Yield Strength (0.2% offset)
Reduction in Area
Compressive Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Rockwell B
Same in both: Shear Modulus 77 GPa11.2 Msi · Tensile Strength (Ultimate) 590 MPa85.6 ksi · Elongation at Break 38% · Shear Strength 400 MPa58 ksi · Hardness, Brinell 185 HB · Hardness, Vickers 195 HV
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
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16 µm/m·K8.9 µin/in·°F · Min Service Temperature -100°C-148 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Same in both: Corrosion Resistance 70 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability Rating (AISI 1212 = 100 %)
Weldability
Castability
Polishability
Same in both: Machinability 35 / 100 · Formability (cold) 55 / 100 · Brazeability / Solderability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 55%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
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.
Manufacturing and finishing
| Capability | ER309LSi | ER316 |
|---|---|---|
| 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.
ER309LSi vs ER316 — frequently asked
What is the difference between ER309LSi and ER316?
Stainless Steel ER309LSi and ER316 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER309LSi runs hotter in service (950°C vs 760°C continuous).
Which is cheaper, ER309LSi or ER316?
ER316 is the lower-cost material: it sits in the premium tier ($$$) while ER309LSi is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
When should I choose ER309LSi over ER316?
Pick ER309LSi when the part sees heat. Pick ER316 when cost is the deciding factor.
Ready to make it?
Upload a CAD file and FabDigit prices the part in ER309LSi and ER316 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.