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Stainless Steel E320LR vs ER308Si

Stainless Steel · grade comparison

Stainless Steel E320LR and ER308Si are both stainless steel grades. ER308Si is the stronger of the two: tensile strength 600 MPa (87 ksi) against 570 MPa (82.7 ksi) for E320LR, about 5% more. ER308Si runs hotter in service (760°C vs 500°C continuous) and ER308Si conducts heat better (15 W/m·K vs 12.6 W/m·K). On the shop floor, ER308Si machines more easily (fair vs poor), ER308Si welds better (excellent vs very good), and ER308Si forms better (good vs fair).

ER308SiChoose it when strength drives the design, or when the part sees heat.

E320LR vs ER308Si: properties

E320LRER308Si

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

193 GPa28 Msi
195 GPa28.3 Msi

Shear Modulus

75 GPa10.9 Msi
77 GPa11.2 Msi

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

570 MPa82.7 ksi
600 MPa87 ksi

Yield Strength (0.2% offset)

390 MPa56.6 ksi
400 MPa58 ksi

Elongation at Break

35%
38%

Reduction in Area

45%
55%

Compressive Strength

395 MPa57.3 ksi
400 MPa58 ksi

Shear Strength

370 MPa53.7 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

220 MPa31.9 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
140 MPa·√m127 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

180 HB
175 HB

Hardness, Vickers

190 HV
185 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Hardness, Rockwell B 88 HRB

Physical

Density and transition temperatures.

Density

8 g/cm³0.29 lb/in³
7.95 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,370°C2,498 °F
1,400°C2,552 °F

Liquidus Temperature

1,425°C2,597 °F
1,450°C2,642 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

12.6 W/m·K7.3 BTU/hr·ft·°F
15 W/m·K8.7 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

14.9 µm/m·K8.3 µin/in·°F
16.5 µm/m·K9.2 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

500°C932 °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

1.6 % IACS
2.4 % IACS

Electrical Resistivity

1.08×10⁻⁶ Ω·m42.5 µΩ·in
7.2×10⁻⁷ Ω·m28.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.1 V
-0.08 V

Corrosion Resistance

80 / 100
68 / 100

Manufacturability

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

Machinability

30 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
45%

Weldability

70 / 100
95 / 100

Formability (cold)

50 / 100
60 / 100

Brazeability / Solderability

50 / 100
60 / 100

Polishability

60 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

95 MJ/kg40,843 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

7.5 kg CO₂/kg
5.5 kg CO₂/kg

Embodied Water

220 L/kg26.4 gal/lb
200 L/kg24 gal/lb

Typical Recycled Content

45%
55%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

71 kN·m/kg
75 kN·m/kg

Specific Stiffness (E / density)

24.1 MN·m/kg
24.5 MN·m/kg

Modulus of Resilience

394 kJ/m³
410 kJ/m³

Thermal Diffusivity

3.2 mm²/s
3.8 mm²/s

Thermal Shock Resistance Index

2
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 scaleER308SiE320LR

Manufacturing and finishing

CapabilityE320LRER308Si
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.

E320LR vs ER308Si — frequently asked

Is ER308Si stronger than E320LR?

Yes. ER308Si has a typical tensile strength of 600 MPa (87 ksi) against 570 MPa (82.7 ksi) for E320LR — about 5% more.

Which is cheaper, E320LR or ER308Si?

ER308Si is the lower-cost material: it sits in the premium tier ($$$) while E320LR is high ($$$$). 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, E320LR or ER308Si?

ER308Si. Its machinability rates fair (40/100) against poor (30/100) for E320LR; for welding the order is ER308Si first (excellent, 95/100) then E320LR (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E320LR and ER308Si 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.