Stainless Steel E240 vs ER308
Stainless Steel · grade comparison
Stainless Steel E240 and ER308 are both stainless steel grades. E240 is the stronger of the two: yield strength 510 MPa (74 ksi) against 400 MPa (58 ksi) for ER308, about 28% more; tensile strength follows at 780 MPa (113 ksi) vs 600 MPa (87 ksi). In exchange, ER308 is the more ductile: elongation 40% versus 26% for E240, and E240 is harder (230 HB vs 185 HB). On the shop floor, ER308 machines more easily (fair vs poor), ER308 welds better (excellent vs very good), and ER308 sits in a lower cost tier (premium, $$$) than E240 (high, $$$$).
E240Choose it when strength drives the design.
ER308Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
E240 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
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Reduction in Area
Compressive Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
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
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
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Galvanic Potential (seawater, vs SCE)
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
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 | E240 | 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.
E240 vs ER308 — frequently asked
Is E240 stronger than ER308?
Yes. E240 has a typical yield strength of 510 MPa (74 ksi) against 400 MPa (58 ksi) for ER308 — about 28% more. Tensile strength is 780 MPa (113 ksi) vs 600 MPa (87 ksi).
Which is cheaper, E240 or ER308?
ER308 is the lower-cost material: it sits in the premium tier ($$$) while E240 is high ($$$$). 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, E240 or ER308?
ER308. Its machinability rates fair (38/100) against poor (25/100) for E240; for welding the order is ER308 first (excellent, 95/100) then E240 (very good, 70/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in E240 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.