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Stainless Steel ER308 vs ER317

Stainless Steel · grade comparison

Stainless Steel ER308 and ER317 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. On the shop floor, ER308 sits in a lower cost tier (premium, $$$) than ER317 (high, $$$$).

ER308Choose it when cost is the deciding factor.

ER308 vs ER317: properties

ER308ER317

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

145 GPa21 Msi
166 GPa24.1 Msi

Poisson's Ratio

0.3
0.29

Elongation at Break

40%
38%

Compressive Strength

400 MPa58 ksi
410 MPa59.5 ksi

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
80 J59 ft·lbf

Hardness, Brinell

185 HB
180 HB

Hardness, Rockwell B

90 HRB
88 HRB

Hardness, Vickers

195 HV
190 HV

Same in both: Elastic (Young's) Modulus 195 GPa28.3 Msi · Shear Modulus 77 GPa11.2 Msi · Tensile Strength (Ultimate) 600 MPa87 ksi · Yield Strength (0.2% offset) 400 MPa58 ksi · Reduction in Area 55% · Shear Strength 400 MPa58 ksi · Fatigue Strength (Endurance Limit) 240 MPa34.8 ksi · Fracture Toughness (K_IC) 150 MPa·√m137 ksi·√in

Physical

Density and transition temperatures.

Density

7.9 g/cm³0.29 lb/in³
7.98 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,400°C2,552 °F
1,370°C2,498 °F

Liquidus Temperature

1,450°C2,642 °F
1,400°C2,552 °F

Thermal

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

Thermal Conductivity

15.5 W/m·K9 BTU/hr·ft·°F
14.5 W/m·K8.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

280 J/g120 BTU/lb
275 J/g118 BTU/lb

Max Service Temperature (continuous)

760°C1,400 °F
800°C1,472 °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

2.4 % IACS
2.2 % IACS

Electrical Resistivity

7.4×10⁻⁷ Ω·m29.1 µΩ·in
7.9×10⁻⁷ Ω·m31.1 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.08 V
-0.05 V

Corrosion Resistance

65 / 100
72 / 100

Manufacturability

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

Machinability

38 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
32%

Weldability

95 / 100
88 / 100

Formability (cold)

55 / 100
60 / 100

Brazeability / Solderability

60 / 100
55 / 100

Polishability

70 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

57 MJ/kg24,506 BTU/lb
58 MJ/kg24,936 BTU/lb

Embodied Carbon (primary production)

5 kg CO₂/kg
4.6 kg CO₂/kg

Typical Recycled Content

45%
55%

Same in both: Embodied Water 130 L/kg15.6 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

76 kN·m/kg
75 kN·m/kg

Specific Stiffness (E / density)

24.7 MN·m/kg
24.4 MN·m/kg

Thermal Diffusivity

3.9 mm²/s
3.6 mm²/s

Same in both: 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 scaleER308ER317

Manufacturing and finishing

CapabilityER308ER317
Default condition——
Relative cost$$$ Premium$$$$ High
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.

ER308 vs ER317 — frequently asked

What is the difference between ER308 and ER317?

Stainless Steel ER308 and ER317 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. On the shop floor, ER308 sits in a lower cost tier (premium, $$$) than ER317 (high, $$$$).

Which is cheaper, ER308 or ER317?

ER308 is the lower-cost material: it sits in the premium tier ($$$) while ER317 is high ($$$$). 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, ER308 or ER317?

ER308. Its machinability rates fair (38/100) against poor (30/100) for ER317; for welding the order is ER308 first (excellent, 95/100) then ER317 (excellent, 88/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER308 and ER317 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.