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Stainless Steel E309H vs ER308H

Stainless Steel · grade comparison

Stainless Steel E309H and ER308H are both stainless steel grades. Both yield at about 420 MPa — strength does not separate them. E309H is harder — 190 HB against 175 HB for ER308H — which matters for wear surfaces and threads. E309H runs hotter in service (980°C vs 800°C continuous). On the shop floor, ER308H forms better (good vs fair) and ER308H sits in a lower cost tier (premium, $$$) than E309H (high, $$$$).

E309HChoose it when surface hardness matters, or when the part sees heat.

ER308HChoose it when cost is the deciding factor.

E309H vs ER308H: properties

E309HER308H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

195 GPa28.3 Msi
196 GPa28.4 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

35%
38%

Reduction in Area

45%
55%

Shear Strength

380 MPa55.1 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
230 MPa33.4 ksi

Fracture Toughness (K_IC)

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

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
85 J62.7 ft·lbf

Hardness, Brinell

190 HB
175 HB

Hardness, Rockwell B

90 HRB
87 HRB

Hardness, Vickers

200 HV
185 HV

Same in both: Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 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 W/m·K8.7 BTU/hr·ft·°F
16.2 W/m·K9.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

15.5 µm/m·K8.6 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)

980°C1,796 °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).

Galvanic Potential (seawater, vs SCE)

-0.1 V
-0.05 V

Corrosion Resistance

62 / 100
58 / 100

Manufacturability

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

Machinability

30 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
40%

Formability (cold)

45 / 100
55 / 100

Brazeability / Solderability

55 / 100
60 / 100

Polishability

55 / 100
65 / 100

Same in both: Weldability 88 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

68 MJ/kg29,235 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

5.2 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
130 L/kg15.6 gal/lb

Same in both: Typical Recycled Content 60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

76 kN·m/kg
75 kN·m/kg

Specific Stiffness (E / density)

24.7 MN·m/kg
24.8 MN·m/kg

Modulus of Resilience

452 kJ/m³
439 kJ/m³

Thermal Diffusivity

3.8 mm²/s
4.1 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 scaleER308HE309H

Manufacturing and finishing

CapabilityE309HER308H
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.

E309H vs ER308H — frequently asked

What is the difference between E309H and ER308H?

Stainless Steel E309H and ER308H are both stainless steel grades. Both yield at about 420 MPa — strength does not separate them. E309H is harder — 190 HB against 175 HB for ER308H — which matters for wear surfaces and threads.

Which is cheaper, E309H or ER308H?

ER308H is the lower-cost material: it sits in the premium tier ($$$) while E309H is high ($$$$). 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, E309H or ER308H?

ER308H. Its machinability rates fair (38/100) against poor (30/100) for E309H.

Ready to make it?

Upload a CAD file and FabDigit prices the part in E309H 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.