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Stainless Steel ER2209 vs ER308

Stainless Steel · grade comparison

Stainless Steel ER2209 and ER308 are both stainless steel grades. ER2209 is the stronger of the two: yield strength 640 MPa (92.8 ksi) against 400 MPa (58 ksi) for ER308, about 60% more; tensile strength follows at 830 MPa (120 ksi) vs 600 MPa (87 ksi). In exchange, ER308 is the more ductile: elongation 40% versus 27% for ER2209, and ER2209 is harder (255 HB vs 185 HB). ER308 runs hotter in service (760°C vs 250°C continuous). On the shop floor, ER308 machines more easily (fair vs poor), ER308 welds better (95 vs 85 out of 100), and ER308 sits in a lower cost tier (premium, $$$) than ER2209 (high, $$$$).

ER2209Choose it when strength drives the design.

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

ER2209 vs ER308: properties

ER2209ER308

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
195 GPa28.3 Msi

Bulk Modulus

160 GPa23.2 Msi
145 GPa21 Msi

Tensile Strength (Ultimate)

830 MPa120 ksi
600 MPa87 ksi

Yield Strength (0.2% offset)

640 MPa92.8 ksi
400 MPa58 ksi

Elongation at Break

27%
40%

Reduction in Area

50%
55%

Compressive Strength

640 MPa92.8 ksi
400 MPa58 ksi

Shear Strength

500 MPa72.5 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

380 MPa55.1 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
150 MPa·√m137 ksi·√in

Charpy V-Notch Impact (RT)

110 J81.1 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

255 HB
185 HB

Hardness, Rockwell C

25 HRC
—

Hardness, Vickers

270 HV
195 HV

Hardness, Rockwell B

—
90 HRB

Same in both: Shear Modulus 77 GPa11.2 Msi · Poisson's Ratio 0.3

Physical

Density and transition temperatures.

Density

7.8 g/cm³0.28 lb/in³
7.9 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,385°C2,525 °F
1,400°C2,552 °F

Liquidus Temperature

1,445°C2,633 °F
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)

13 µm/m·K7.2 µin/in·°F
16.9 µm/m·K9.4 µin/in·°F

Latent Heat of Fusion

265 J/g114 BTU/lb
280 J/g120 BTU/lb

Max Service Temperature (continuous)

250°C482 °F
760°C1,400 °F

Min Service Temperature

-50°C-58 °F
-196°C-321 °F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.2 % IACS
2.4 % IACS

Electrical Resistivity

8×10⁻⁷ Ω·m31.5 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)

-0.15 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

28 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

22%
45%

Weldability

85 / 100
95 / 100

Formability (cold)

45 / 100
55 / 100

Brazeability / Solderability

45 / 100
60 / 100

Polishability

65 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

65 MJ/kg27,945 BTU/lb
57 MJ/kg24,506 BTU/lb

Embodied Carbon (primary production)

4.8 kg CO₂/kg
5 kg CO₂/kg

Embodied Water

180 L/kg21.6 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)

106 kN·m/kg
76 kN·m/kg

Specific Stiffness (E / density)

25.6 MN·m/kg
24.7 MN·m/kg

Modulus of Resilience

1,024 kJ/m³
410 kJ/m³

Thermal Diffusivity

3.8 mm²/s
3.9 mm²/s

Thermal Shock Resistance Index

5
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 scaleER308ER2209

Manufacturing and finishing

CapabilityER2209ER308
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.

ER2209 vs ER308 — frequently asked

Is ER2209 stronger than ER308?

Yes. ER2209 has a typical yield strength of 640 MPa (92.8 ksi) against 400 MPa (58 ksi) for ER308 — about 60% more. Tensile strength is 830 MPa (120 ksi) vs 600 MPa (87 ksi).

Which is cheaper, ER2209 or ER308?

ER308 is the lower-cost material: it sits in the premium tier ($$$) while ER2209 is high ($$$$). 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, ER2209 or ER308?

ER308. Its machinability rates fair (38/100) against poor (28/100) for ER2209; for welding the order is ER308 first (excellent, 95/100) then ER2209 (excellent, 85/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER2209 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.