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Stainless Steel E308LMo vs ER308

Stainless Steel · grade comparison

Stainless Steel E308LMo and ER308 are both stainless steel grades. ER308 is the stronger of the two: tensile strength 600 MPa (87 ksi) against 560 MPa (81.2 ksi) for E308LMo, about 7% more. ER308 runs hotter in service (760°C vs 400°C continuous). On the shop floor, ER308 sits in a lower cost tier (premium, $$$) than E308LMo (high, $$$$).

ER308Choose it when strength drives the design, or when the part sees heat.

E308LMo vs ER308: properties

E308LMoER308

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

160 GPa23.2 Msi
145 GPa21 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

560 MPa81.2 ksi
600 MPa87 ksi

Shear Strength

350 MPa50.8 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

145 MPa·√m132 ksi·√in
150 MPa·√m137 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

180 HB
185 HB

Hardness, Rockwell B

89 HRB
90 HRB

Hardness, Vickers

190 HV
195 HV

Same in both: Elastic (Young's) Modulus 195 GPa28.3 Msi · Shear Modulus 77 GPa11.2 Msi · Yield Strength (0.2% offset) 400 MPa58 ksi · Elongation at Break 40% · 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

15 W/m·K8.7 BTU/hr·ft·°F
15.5 W/m·K9 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

16.5 µm/m·K9.2 µin/in·°F
16.9 µm/m·K9.4 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
280 J/g120 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
760°C1,400 °F

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

2.3 % IACS
2.4 % IACS

Electrical Resistivity

7.5×10⁻⁷ Ω·m29.5 µΩ·in
7.4×10⁻⁷ Ω·m29.1 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.05 V
-0.08 V

Corrosion Resistance

72 / 100
65 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

35 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
45%

Weldability

90 / 100
95 / 100

Formability (cold)

58 / 100
55 / 100

Brazeability / Solderability

55 / 100
60 / 100

Same in both: Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
57 MJ/kg24,506 BTU/lb

Embodied Carbon (primary production)

4.8 kg CO₂/kg
5 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

60%
45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

71 kN·m/kg
76 kN·m/kg

Thermal Diffusivity

3.8 mm²/s
3.9 mm²/s

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.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scaleER308E308LMo

Manufacturing and finishing

CapabilityE308LMoER308
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.

E308LMo vs ER308 — frequently asked

Is ER308 stronger than E308LMo?

Yes. ER308 has a typical tensile strength of 600 MPa (87 ksi) against 560 MPa (81.2 ksi) for E308LMo — about 7% more.

Which is cheaper, E308LMo or ER308?

ER308 is the lower-cost material: it sits in the premium tier ($$$) while E308LMo is high ($$$$). 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, E308LMo or ER308?

ER308. Its weldability rates excellent (95/100) against excellent (90/100) for E308LMo.

Ready to make it?

Upload a CAD file and FabDigit prices the part in E308LMo 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.