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Stainless Steel ER308H vs ER316LSi

Stainless Steel · grade comparison

Stainless Steel ER308H and ER316LSi are both stainless steel grades. Both yield at about 415 MPa — strength does not separate them. ER316LSi is harder — 190 HB against 175 HB for ER308H — which matters for wear surfaces and threads. ER308H runs hotter in service (800°C vs 400°C continuous). On the shop floor, ER316LSi forms better (very good vs good).

ER308HChoose it when the part sees heat.

ER316LSiChoose it when surface hardness matters.

ER308H vs ER316LSi: properties

ER308HER316LSi

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

196 GPa28.4 Msi
195 GPa28.3 Msi

Bulk Modulus

160 GPa23.2 Msi
155 GPa22.5 Msi

Tensile Strength (Ultimate)

590 MPa85.6 ksi
580 MPa84.1 ksi

Yield Strength (0.2% offset)

415 MPa60.2 ksi
420 MPa60.9 ksi

Elongation at Break

38%
40%

Shear Strength

400 MPa58 ksi
350 MPa50.8 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

180 MPa·√m164 ksi·√in
130 MPa·√m118 ksi·√in

Charpy V-Notch Impact (RT)

85 J62.7 ft·lbf
95 J70.1 ft·lbf

Hardness, Brinell

175 HB
190 HB

Hardness, Rockwell B

87 HRB
90 HRB

Hardness, Vickers

185 HV
200 HV

Same in both: Shear Modulus 77 GPa11.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 55% · Compressive Strength 420 MPa60.9 ksi

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
1,390°C2,534 °F

Liquidus Temperature

1,450°C2,642 °F
1,440°C2,624 °F

Thermal

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

Thermal Conductivity

16.2 W/m·K9.4 BTU/hr·ft·°F
15 W/m·K8.7 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

16.5 µm/m·K9.2 µin/in·°F
16 µm/m·K8.9 µin/in·°F

Latent Heat of Fusion

285 J/g123 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

800°C1,472 °F
400°C752 °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
2.3 % IACS

Electrical Resistivity

7.2×10⁻⁷ Ω·m28.3 µΩ·in
7.4×10⁻⁷ Ω·m29.1 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

58 / 100
76 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.05 V

Manufacturability

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

Weldability

88 / 100
95 / 100

Formability (cold)

55 / 100
70 / 100

Brazeability / Solderability

60 / 100
55 / 100

Polishability

65 / 100
70 / 100

Same in both: Machinability 38 / 100 · Machinability Rating (AISI 1212 = 100 %) 40%

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

4.5 kg CO₂/kg
6.5 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
160 L/kg19.2 gal/lb

Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Typical Recycled Content 60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

75 kN·m/kg
73 kN·m/kg

Specific Stiffness (E / density)

24.8 MN·m/kg
24.4 MN·m/kg

Modulus of Resilience

439 kJ/m³
452 kJ/m³

Thermal Diffusivity

4.1 mm²/s
3.8 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 scaleER308HER316LSi

Manufacturing and finishing

CapabilityER308HER316LSi
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.

ER308H vs ER316LSi — frequently asked

What is the difference between ER308H and ER316LSi?

Stainless Steel ER308H and ER316LSi are both stainless steel grades. Both yield at about 415 MPa — strength does not separate them. ER316LSi is harder — 190 HB against 175 HB for ER308H — which matters for wear surfaces and threads.

Which is cheaper, ER308H or ER316LSi?

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 welds better, ER308H or ER316LSi?

ER316LSi. Its weldability rates excellent (95/100) against excellent (88/100) for ER308H.

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER308H and ER316LSi 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.