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Stainless Steel E320 vs ER308

Stainless Steel · grade comparison

Stainless Steel E320 and ER308 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER308 is the more ductile: elongation 40% versus 35% for E320. ER308 runs hotter in service (760°C vs 500°C continuous) and ER308 conducts heat better (15.5 W/m·K vs 11.8 W/m·K). On the shop floor, ER308 machines more easily (fair vs poor), ER308 welds better (excellent vs good), and ER308 sits in a lower cost tier (premium, $$$) than E320 (high, $$$$).

ER308Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

E320 vs ER308: properties

E320ER308

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

Bulk Modulus

160 GPa23.2 Msi
145 GPa21 Msi

Tensile Strength (Ultimate)

610 MPa88.5 ksi
600 MPa87 ksi

Elongation at Break

35%
40%

Reduction in Area

45%
55%

Fatigue Strength (Endurance Limit)

215 MPa31.2 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

130 MPa·√m118 ksi·√in
150 MPa·√m137 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

180 HB
185 HB

Hardness, Rockwell B

88 HRB
90 HRB

Hardness, Vickers

190 HV
195 HV

Same in both: Poisson's Ratio 0.3 · Yield Strength (0.2% offset) 400 MPa58 ksi · Compressive Strength 400 MPa58 ksi · Shear Strength 400 MPa58 ksi

Physical

Density and transition temperatures.

Density

8.08 g/cm³0.29 lb/in³
7.9 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

11.8 W/m·K6.8 BTU/hr·ft·°F
15.5 W/m·K9 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

14.8 µm/m·K8.2 µin/in·°F
16.9 µm/m·K9.4 µin/in·°F

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 · Latent Heat of Fusion 280 J/g120 BTU/lb · 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
7.4×10⁻⁷ Ω·m29.1 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
65 / 100

Manufacturability

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

Machinability

24 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

28%
45%

Weldability

55 / 100
95 / 100

Formability (cold)

50 / 100
55 / 100

Brazeability / Solderability

55 / 100
60 / 100

Polishability

65 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

95 MJ/kg40,843 BTU/lb
57 MJ/kg24,506 BTU/lb

Embodied Carbon (primary production)

7.5 kg CO₂/kg
5 kg CO₂/kg

Embodied Water

180 L/kg21.6 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

40%
45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

75 kN·m/kg
76 kN·m/kg

Specific Stiffness (E / density)

23.9 MN·m/kg
24.7 MN·m/kg

Modulus of Resilience

415 kJ/m³
410 kJ/m³

Thermal Diffusivity

2.9 mm²/s
3.9 mm²/s

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.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scaleER308E320

Manufacturing and finishing

CapabilityE320ER308
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.

E320 vs ER308 — frequently asked

What is the difference between E320 and ER308?

Stainless Steel E320 and ER308 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER308 is the more ductile: elongation 40% versus 35% for E320.

Which is cheaper, E320 or ER308?

ER308 is the lower-cost material: it sits in the premium tier ($$$) while E320 is high ($$$$). 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, E320 or ER308?

ER308. Its machinability rates fair (38/100) against poor (24/100) for E320; for welding the order is ER308 first (excellent, 95/100) then E320 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E320 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.