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Stainless Steel E2594 vs ER308Si

Stainless Steel · grade comparison

Stainless Steel E2594 and ER308Si are both stainless steel grades. E2594 is the stronger of the two: yield strength 680 MPa (98.6 ksi) against 400 MPa (58 ksi) for ER308Si, about 70% more; tensile strength follows at 870 MPa (126 ksi) vs 600 MPa (87 ksi). In exchange, ER308Si is the more ductile: elongation 38% versus 26% for E2594, and E2594 is harder (270 HB vs 175 HB). ER308Si runs hotter in service (760°C vs 250°C continuous). On the shop floor, ER308Si machines more easily (fair vs poor), ER308Si welds better (excellent vs very good), and ER308Si sits in a lower cost tier (premium, $$$) than E2594 (high, $$$$).

E2594Choose it when strength drives the design.

ER308SiChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

E2594 vs ER308Si: properties

E2594ER308Si

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
195 GPa28.3 Msi

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

870 MPa126 ksi
600 MPa87 ksi

Yield Strength (0.2% offset)

680 MPa98.6 ksi
400 MPa58 ksi

Elongation at Break

26%
38%

Reduction in Area

45%
55%

Shear Strength

520 MPa75.4 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

380 MPa55.1 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
140 MPa·√m127 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

270 HB
175 HB

Hardness, Rockwell C

27 HRC
—

Hardness, Vickers

285 HV
185 HV

Compressive Strength

—
400 MPa58 ksi

Hardness, Rockwell B

—
88 HRB

Same in both: Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,350°C2,462 °F
1,400°C2,552 °F

Liquidus Temperature

1,440°C2,624 °F
1,450°C2,642 °F

Thermal

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

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: Thermal Conductivity 15 W/m·K8.7 BTU/hr·ft·°F · Latent Heat of Fusion 270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

2.2 % IACS
2.4 % IACS

Electrical Resistivity

8×10⁻⁷ Ω·m31.5 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)

-0.12 V
-0.08 V

Corrosion Resistance

86 / 100
68 / 100

Manufacturability

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

Machinability

25 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

20%
45%

Weldability

80 / 100
95 / 100

Formability (cold)

25 / 100
60 / 100

Polishability

60 / 100
70 / 100

Brazeability / Solderability

—
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

62 MJ/kg26,655 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

5.2 kg CO₂/kg
5.5 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
200 L/kg24 gal/lb

Typical Recycled Content

45%
55%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

112 kN·m/kg
75 kN·m/kg

Specific Stiffness (E / density)

25.6 MN·m/kg
24.5 MN·m/kg

Modulus of Resilience

1,156 kJ/m³
410 kJ/m³

Thermal Diffusivity

4 mm²/s
3.8 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 scaleER308SiE2594

Manufacturing and finishing

CapabilityE2594ER308Si
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.

E2594 vs ER308Si — frequently asked

Is E2594 stronger than ER308Si?

Yes. E2594 has a typical yield strength of 680 MPa (98.6 ksi) against 400 MPa (58 ksi) for ER308Si — about 70% more. Tensile strength is 870 MPa (126 ksi) vs 600 MPa (87 ksi).

Which is cheaper, E2594 or ER308Si?

ER308Si is the lower-cost material: it sits in the premium tier ($$$) while E2594 is high ($$$$). 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, E2594 or ER308Si?

ER308Si. Its machinability rates fair (40/100) against poor (25/100) for E2594; for welding the order is ER308Si first (excellent, 95/100) then E2594 (very good, 80/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E2594 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.