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Stainless Steel E309 vs ER308H

Stainless Steel · grade comparison

Stainless Steel E309 and ER308H are both stainless steel grades. Both yield at about 420 MPa — strength does not separate them. E309 is harder — 185 HB against 175 HB for ER308H — which matters for wear surfaces and threads. On the shop floor, ER308H forms better (good vs fair) and ER308H sits in a lower cost tier (premium, $$$) than E309 (high, $$$$).

E309Choose it when surface hardness matters.

ER308HChoose it when cost is the deciding factor.

E309 vs ER308H: properties

E309ER308H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

150 GPa21.8 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

600 MPa87 ksi
590 MPa85.6 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
415 MPa60.2 ksi

Elongation at Break

37%
38%

Reduction in Area

50%
55%

Shear Strength

380 MPa55.1 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
230 MPa33.4 ksi

Fracture Toughness (K_IC)

150 MPa·√m137 ksi·√in
180 MPa·√m164 ksi·√in

Charpy V-Notch Impact (RT)

50 J36.9 ft·lbf
85 J62.7 ft·lbf

Hardness, Brinell

185 HB
175 HB

Hardness, Rockwell B

90 HRB
87 HRB

Hardness, Rockwell C

11 HRC
—

Hardness, Vickers

195 HV
185 HV

Same in both: Elastic (Young's) Modulus 196 GPa28.4 Msi · Shear Modulus 77 GPa11.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 420 MPa60.9 ksi

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

15.5 W/m·K9 BTU/hr·ft·°F
16.2 W/m·K9.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

15 µm/m·K8.3 µin/in·°F
16.5 µm/m·K9.2 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

850°C1,562 °F
800°C1,472 °F

Min Service Temperature

-100°C-148 °F
-196°C-321 °F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.2 % IACS
2.4 % IACS

Electrical Resistivity

7.8×10⁻⁷ Ω·m30.7 µΩ·in
7.2×10⁻⁷ Ω·m28.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

66 / 100
58 / 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.

Machinability

35 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

38%
40%

Weldability

90 / 100
88 / 100

Formability (cold)

45 / 100
55 / 100

Polishability

55 / 100
65 / 100

Brazeability / Solderability

—
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Embodied Carbon (primary production)

6 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

120 L/kg14.4 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

55%
60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

76 kN·m/kg
75 kN·m/kg

Modulus of Resilience

450 kJ/m³
439 kJ/m³

Thermal Diffusivity

3.9 mm²/s
4.1 mm²/s

Same in both: Specific Stiffness (E / density) 24.8 MN·m/kg · 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 scaleER308HE309

Manufacturing and finishing

CapabilityE309ER308H
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.

E309 vs ER308H — frequently asked

What is the difference between E309 and ER308H?

Stainless Steel E309 and ER308H are both stainless steel grades. Both yield at about 420 MPa — strength does not separate them. E309 is harder — 185 HB against 175 HB for ER308H — which matters for wear surfaces and threads.

Which is cheaper, E309 or ER308H?

ER308H is the lower-cost material: it sits in the premium tier ($$$) while E309 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

When should I choose E309 over ER308H?

Pick E309 when surface hardness matters. Pick ER308H when cost is the deciding factor.

Ready to make it?

Upload a CAD file and FabDigit prices the part in E309 and ER308H 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.