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Stainless Steel ER308 vs ER383

Stainless Steel · grade comparison

Stainless Steel ER308 and ER383 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER308 runs hotter in service (760°C vs 550°C continuous) and ER308 conducts heat better (15.5 W/m·K vs 12 W/m·K). On the shop floor, ER308 machines more easily (fair vs poor), ER308 welds better (excellent vs very good), and ER308 sits in a lower cost tier (premium, $$$) than ER383 (high, $$$$).

ER308Choose it when the part sees heat, or when the part is machined in volume.

ER308 vs ER383: properties

ER308ER383

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

77 GPa11.2 Msi
75 GPa10.9 Msi

Bulk Modulus

145 GPa21 Msi
163 GPa23.6 Msi

Yield Strength (0.2% offset)

400 MPa58 ksi
390 MPa56.6 ksi

Elongation at Break

40%
38%

Reduction in Area

55%
50%

Compressive Strength

400 MPa58 ksi
395 MPa57.3 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
230 MPa33.4 ksi

Fracture Toughness (K_IC)

150 MPa·√m137 ksi·√in
—

Same in both: Elastic (Young's) Modulus 195 GPa28.3 Msi · Poisson's Ratio 0.3 · Tensile Strength (Ultimate) 600 MPa87 ksi · Shear Strength 400 MPa58 ksi · Charpy V-Notch Impact (RT) 90 J66.4 ft·lbf · Hardness, Brinell 185 HB · Hardness, Rockwell B 90 HRB · Hardness, Vickers 195 HV

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,400°C2,552 °F
1,350°C2,462 °F

Liquidus Temperature

1,450°C2,642 °F
1,380°C2,516 °F

Thermal

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

Thermal Conductivity

15.5 W/m·K9 BTU/hr·ft·°F
12 W/m·K6.9 BTU/hr·ft·°F

Specific Heat Capacity

500 J/kg·K0.12 BTU/lb·°F
470 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

16.9 µm/m·K9.4 µin/in·°F
14.5 µm/m·K8.1 µin/in·°F

Max Service Temperature (continuous)

760°C1,400 °F
550°C1,022 °F

Same in both: Latent Heat of Fusion 280 J/g120 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.4 % IACS
1.7 % IACS

Electrical Resistivity

7.4×10⁻⁷ Ω·m29.1 µΩ·in
9.9×10⁻⁷ Ω·m39 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.08 V
-0.1 V

Corrosion Resistance

65 / 100
83 / 100

Manufacturability

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

Machinability

38 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
25%

Weldability

95 / 100
70 / 100

Formability (cold)

55 / 100
50 / 100

Brazeability / Solderability

60 / 100
55 / 100

Same in both: Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Embodied Carbon (primary production)

5 kg CO₂/kg
7.5 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

45%
40%

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

Modulus of Resilience

410 kJ/m³
390 kJ/m³

Thermal Diffusivity

3.9 mm²/s
3.2 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 scaleER308ER383

Manufacturing and finishing

CapabilityER308ER383
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 ER383 — frequently asked

What is the difference between ER308 and ER383?

Stainless Steel ER308 and ER383 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER308 runs hotter in service (760°C vs 550°C continuous) and ER308 conducts heat better (15.5 W/m·K vs 12 W/m·K).

Which is cheaper, ER308 or ER383?

ER308 is the lower-cost material: it sits in the premium tier ($$$) while ER383 is high ($$$$). 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 ER383?

ER308. Its machinability rates fair (38/100) against poor (22/100) for ER383; for welding the order is ER308 first (excellent, 95/100) then ER383 (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER308 and ER383 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.