FabDigitFabDigit

Stainless Steel ER308Si vs ER410NiMo

Stainless Steel · grade comparison

Stainless Steel ER308Si and ER410NiMo are both stainless steel grades. ER410NiMo is the stronger of the two: yield strength 830 MPa (120 ksi) against 400 MPa (58 ksi) for ER308Si, about 108% more; tensile strength follows at 950 MPa (138 ksi) vs 600 MPa (87 ksi). In exchange, ER308Si is the more ductile: elongation 38% versus 14% for ER410NiMo, and ER410NiMo is harder (355 HB vs 175 HB). ER308Si runs hotter in service (760°C vs 400°C continuous) and ER410NiMo conducts heat better (25 W/m·K vs 15 W/m·K). On the shop floor, ER308Si machines more easily (fair vs poor) and ER308Si welds better (excellent vs good).

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

ER410NiMoChoose it when strength drives the design.

ER308Si vs ER410NiMo: properties

ER308SiER410NiMo

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

195 GPa28.3 Msi
200 GPa29 Msi

Shear Modulus

77 GPa11.2 Msi
78 GPa11.3 Msi

Tensile Strength (Ultimate)

600 MPa87 ksi
950 MPa138 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
830 MPa120 ksi

Elongation at Break

38%
14%

Reduction in Area

55%
45%

Compressive Strength

400 MPa58 ksi
—

Shear Strength

400 MPa58 ksi
580 MPa84.1 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
440 MPa63.8 ksi

Fracture Toughness (K_IC)

140 MPa·√m127 ksi·√in
65 MPa·√m59.2 ksi·√in

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
32 J23.6 ft·lbf

Hardness, Brinell

175 HB
355 HB

Hardness, Rockwell B

88 HRB
—

Hardness, Vickers

185 HV
375 HV

Hardness, Rockwell C

—
38 HRC

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,400°C2,552 °F
1,440°C2,624 °F

Liquidus Temperature

1,450°C2,642 °F
1,510°C2,750 °F

Thermal

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

Thermal Conductivity

15 W/m·K8.7 BTU/hr·ft·°F
25 W/m·K14.4 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

16.5 µm/m·K9.2 µin/in·°F
10.8 µm/m·K6 µin/in·°F

Max Service Temperature (continuous)

760°C1,400 °F
400°C752 °F

Min Service Temperature

-196°C-321 °F
-20°C-4 °F

Same in both: Latent Heat of Fusion 270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

2.4 % IACS
2.9 % IACS

Electrical Resistivity

7.2×10⁻⁷ Ω·m28.3 µΩ·in
6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.08 V
-0.3 V

Corrosion Resistance

68 / 100
42 / 100

Manufacturability

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

Machinability

40 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
22%

Weldability

95 / 100
65 / 100

Formability (cold)

60 / 100
25 / 100

Brazeability / Solderability

60 / 100
45 / 100

Polishability

70 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

5.5 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

200 L/kg24 gal/lb
140 L/kg16.8 gal/lb

Typical Recycled Content

55%
40%

Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

75 kN·m/kg
123 kN·m/kg

Specific Stiffness (E / density)

24.5 MN·m/kg
25.8 MN·m/kg

Modulus of Resilience

410 kJ/m³
1,722 kJ/m³

Thermal Diffusivity

3.8 mm²/s
7 mm²/s

Thermal Shock Resistance Index

3
11

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 scaleER308SiER410NiMo

Manufacturing and finishing

CapabilityER308SiER410NiMo
Default condition——
Relative cost$$$ Premium$$$ 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.

ER308Si vs ER410NiMo — frequently asked

Is ER410NiMo stronger than ER308Si?

Yes. ER410NiMo has a typical yield strength of 830 MPa (120 ksi) against 400 MPa (58 ksi) for ER308Si — about 108% more. Tensile strength is 950 MPa (138 ksi) vs 600 MPa (87 ksi).

Which is cheaper, ER308Si or ER410NiMo?

Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, ER308Si or ER410NiMo?

ER308Si. Its machinability rates fair (40/100) against poor (22/100) for ER410NiMo; for welding the order is ER308Si first (excellent, 95/100) then ER410NiMo (good, 65/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER308Si and ER410NiMo 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.