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Stainless Steel ER308H vs ER308LSi

Stainless Steel · grade comparison

Stainless Steel ER308H and ER308LSi are both stainless steel grades. Both yield at about 415 MPa — strength does not separate them. ER308H is harder — 175 HB against 165 HB for ER308LSi — which matters for wear surfaces and threads. ER308H runs hotter in service (800°C vs 425°C continuous). On the shop floor, ER308LSi forms better (very good vs good).

ER308HChoose it when surface hardness matters, or when the part sees heat.

ER308H vs ER308LSi: properties

ER308HER308LSi

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

196 GPa28.4 Msi
195 GPa28.3 Msi

Shear Modulus

77 GPa11.2 Msi
75 GPa10.9 Msi

Bulk Modulus

160 GPa23.2 Msi
152 GPa22 Msi

Tensile Strength (Ultimate)

590 MPa85.6 ksi
580 MPa84.1 ksi

Yield Strength (0.2% offset)

415 MPa60.2 ksi
400 MPa58 ksi

Compressive Strength

420 MPa60.9 ksi
400 MPa58 ksi

Shear Strength

400 MPa58 ksi
370 MPa53.7 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

180 MPa·√m164 ksi·√in
160 MPa·√m146 ksi·√in

Charpy V-Notch Impact (RT)

85 J62.7 ft·lbf
80 J59 ft·lbf

Hardness, Brinell

175 HB
165 HB

Hardness, Rockwell B

87 HRB
85 HRB

Hardness, Vickers

185 HV
180 HV

Same in both: Poisson's Ratio 0.29 · Elongation at Break 38% · Reduction in Area 55%

Physical

Density and transition temperatures.

Same in both: Density 7.9 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °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

Latent Heat of Fusion

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

Max Service Temperature (continuous)

800°C1,472 °F
425°C797 °F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16.5 µm/m·K9.2 µin/in·°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).

Galvanic Potential (seawater, vs SCE)

-0.05 V
-0.08 V

Corrosion Resistance

58 / 100
66 / 100

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

Same in both: Machinability 38 / 100 · Machinability Rating (AISI 1212 = 100 %) 40% · Brazeability / Solderability 60 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
60 MJ/kg25,795 BTU/lb

Embodied Carbon (primary production)

4.5 kg CO₂/kg
5.5 kg CO₂/kg

Typical Recycled Content

60%
65%

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

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
24.7 MN·m/kg

Modulus of Resilience

439 kJ/m³
410 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 scaleER308HER308LSi

Manufacturing and finishing

CapabilityER308HER308LSi
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 ER308LSi — frequently asked

What is the difference between ER308H and ER308LSi?

Stainless Steel ER308H and ER308LSi are both stainless steel grades. Both yield at about 415 MPa — strength does not separate them. ER308H is harder — 175 HB against 165 HB for ER308LSi — which matters for wear surfaces and threads.

Which is cheaper, ER308H or ER308LSi?

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 ER308LSi?

ER308LSi. 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 ER308LSi 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.