FabDigitFabDigit

Stainless Steel ER308H vs ER320

Stainless Steel · grade comparison

Stainless Steel ER308H and ER320 are both stainless steel grades. ER308H is the stronger of the two: yield strength 415 MPa (60.2 ksi) against 380 MPa (55.1 ksi) for ER320, about 9% more. ER308H is the more ductile: elongation 38% versus 34% for ER320. ER308H runs hotter in service (800°C vs 500°C continuous) and ER308H conducts heat better (16.2 W/m·K vs 12.6 W/m·K). On the shop floor, ER308H machines more easily (fair vs poor), ER308H welds better (excellent vs good), and ER308H sits in a lower cost tier (premium, $$$) than ER320 (high, $$$$).

ER308HChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

ER308H vs ER320: properties

ER308HER320

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

196 GPa28.4 Msi
193 GPa28 Msi

Shear Modulus

77 GPa11.2 Msi
75 GPa10.9 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

590 MPa85.6 ksi
585 MPa84.8 ksi

Yield Strength (0.2% offset)

415 MPa60.2 ksi
380 MPa55.1 ksi

Elongation at Break

38%
34%

Reduction in Area

55%
45%

Compressive Strength

420 MPa60.9 ksi
385 MPa55.8 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
235 MPa34.1 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
90 J66.4 ft·lbf

Hardness, Brinell

175 HB
180 HB

Hardness, Rockwell B

87 HRB
88 HRB

Hardness, Vickers

185 HV
190 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Shear Strength 400 MPa58 ksi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,400°C2,552 °F
1,370°C2,498 °F

Liquidus Temperature

1,450°C2,642 °F
1,400°C2,552 °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
12.6 W/m·K7.3 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

285 J/g123 BTU/lb
275 J/g118 BTU/lb

Max Service Temperature (continuous)

800°C1,472 °F
500°C932 °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
1.6 % IACS

Electrical Resistivity

7.2×10⁻⁷ Ω·m28.3 µΩ·in
1.08×10⁻⁶ Ω·m42.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.05 V
-0.1 V

Corrosion Resistance

58 / 100
80 / 100

Manufacturability

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

Machinability

38 / 100
26 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
28%

Weldability

88 / 100
68 / 100

Formability (cold)

55 / 100
60 / 100

Brazeability / Solderability

60 / 100
55 / 100

Polishability

65 / 100
70 / 100

Castability

—
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
95 MJ/kg40,843 BTU/lb

Embodied Carbon (primary production)

4.5 kg CO₂/kg
8.5 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

60%
30%

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
24.1 MN·m/kg

Modulus of Resilience

439 kJ/m³
374 kJ/m³

Thermal Diffusivity

4.1 mm²/s
3.1 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 scaleER308HER320

Manufacturing and finishing

CapabilityER308HER320
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.

ER308H vs ER320 — frequently asked

Is ER308H stronger than ER320?

Yes. ER308H has a typical yield strength of 415 MPa (60.2 ksi) against 380 MPa (55.1 ksi) for ER320 — about 9% more. Tensile strength is 590 MPa (85.6 ksi) vs 585 MPa (84.8 ksi).

Which is cheaper, ER308H or ER320?

ER308H is the lower-cost material: it sits in the premium tier ($$$) while ER320 is high ($$$$). 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, ER308H or ER320?

ER308H. Its machinability rates fair (38/100) against poor (26/100) for ER320; for welding the order is ER308H first (excellent, 88/100) then ER320 (good, 68/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER308H and ER320 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.