Stainless Steel E309 vs ER308
Stainless Steel · grade comparison
Stainless Steel E309 and ER308 are both stainless steel grades. Both yield at about 420 MPa — strength does not separate them. E309 runs hotter in service (850°C vs 760°C continuous). On the shop floor, ER308 forms better (good vs fair) and ER308 sits in a lower cost tier (premium, $$$) than E309 (high, $$$$).
E309Choose it when the part sees heat.
ER308Choose it when cost is the deciding factor.
E309 vs ER308: 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)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Rockwell C
Same in both: Shear Modulus 77 GPa11.2 Msi · Tensile Strength (Ultimate) 600 MPa87 ksi · Fracture Toughness (K_IC) 150 MPa·√m137 ksi·√in · Hardness, Brinell 185 HB · Hardness, Rockwell B 90 HRB · Hardness, Vickers 195 HV
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 Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Conductivity 15.5 W/m·K9 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°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)
Polishability
Brazeability / Solderability
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 Stiffness (E / density)
Modulus of Resilience
Same in both: Specific Strength (UTS / density) 76 kN·m/kg · Thermal Diffusivity 3.9 mm²/s · 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 | E309 | ER308 |
|---|---|---|
| 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.
E309 vs ER308 — frequently asked
What is the difference between E309 and ER308?
Stainless Steel E309 and ER308 are both stainless steel grades. Both yield at about 420 MPa — strength does not separate them. E309 runs hotter in service (850°C vs 760°C continuous).
Which is cheaper, E309 or ER308?
ER308 is the lower-cost material: it sits in the premium tier ($$$) while E309 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which welds better, E309 or ER308?
ER308. Its weldability rates excellent (95/100) against excellent (90/100) for E309.
Ready to make it?
Upload a CAD file and FabDigit prices the part in E309 and ER308 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.