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Steel E309L-16 vs ER70S-2

Steel · grade comparison

Steel E309L-16 and ER70S-2 are both steel grades. ER70S-2 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 410 MPa (59.5 ksi) for E309L-16, about 10% more. In exchange, E309L-16 is the more ductile: elongation 38% versus 28% for ER70S-2, and E309L-16 is harder (200 HB vs 155 HB). E309L-16 runs hotter in service (650°C vs 400°C continuous) and ER70S-2 conducts heat better (48 W/m·K vs 15 W/m·K). On the shop floor, ER70S-2 machines more easily (good vs fair) and ER70S-2 sits in a lower cost tier (standard, $$) than E309L-16 (premium, $$$).

E309L-16Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

ER70S-2Choose it when strength drives the design, or when the part is machined in volume.

E309L-16 vs ER70S-2: properties

E309L-16ER70S-2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

196 GPa28.4 Msi
205 GPa29.7 Msi

Shear Modulus

76 GPa11 Msi
80 GPa11.6 Msi

Poisson's Ratio

0.28
0.29

Tensile Strength (Ultimate)

580 MPa84.1 ksi
560 MPa81.2 ksi

Yield Strength (0.2% offset)

410 MPa59.5 ksi
450 MPa65.3 ksi

Elongation at Break

38%
28%

Reduction in Area

45%
68%

Compressive Strength

415 MPa60.2 ksi
450 MPa65.3 ksi

Shear Strength

380 MPa55.1 ksi
345 MPa50 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
235 MPa34.1 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
115 MPa·√m105 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
120 J88.5 ft·lbf

Hardness, Brinell

200 HB
155 HB

Hardness, Rockwell B

92 HRB
82 HRB

Hardness, Vickers

210 HV
163 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Density

7.8 g/cm³0.28 lb/in³
7.85 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,400°C2,552 °F
1,470°C2,678 °F

Liquidus Temperature

1,450°C2,642 °F
1,520°C2,768 °F

Thermal

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

Thermal Conductivity

15 W/m·K8.7 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°F

Specific Heat Capacity

500 J/kg·K0.12 BTU/lb·°F
470 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

16 µm/m·K8.9 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Latent Heat of Fusion

280 J/g120 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

650°C1,202 °F
400°C752 °F

Min Service Temperature

-100°C-148 °F
-30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.2 % IACS
10.5 % IACS

Electrical Resistivity

7.8×10⁻⁷ Ω·m30.7 µΩ·in
1.6×10⁻⁷ Ω·m6.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.1 V
-0.61 V

Corrosion Resistance

66 / 100
10 / 100

Manufacturability

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

Machinability

35 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
65%

Weldability

90 / 100
98 / 100

Formability (cold)

55 / 100
70 / 100

Polishability

55 / 100
50 / 100

Brazeability / Solderability

—
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

5 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
35 L/kg4.2 gal/lb

Typical Recycled Content

55%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

74 kN·m/kg
71 kN·m/kg

Specific Stiffness (E / density)

25.1 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

429 kJ/m³
494 kJ/m³

Thermal Diffusivity

3.8 mm²/s
13 mm²/s

Thermal Shock Resistance Index

3
10

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleER70S-2E309L-16

Manufacturing and finishing

CapabilityE309L-16ER70S-2
Default condition——
Relative cost$$$ Premium$$ Standard
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

E309L-16 vs ER70S-2 — frequently asked

Is ER70S-2 stronger than E309L-16?

Yes. ER70S-2 has a typical yield strength of 450 MPa (65.3 ksi) against 410 MPa (59.5 ksi) for E309L-16 — about 10% more. Tensile strength is 560 MPa (81.2 ksi) vs 580 MPa (84.1 ksi).

Which is cheaper, E309L-16 or ER70S-2?

ER70S-2 is the lower-cost material: it sits in the standard tier ($$) while E309L-16 is premium ($$$). 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, E309L-16 or ER70S-2?

ER70S-2. Its machinability rates good (62/100) against fair (35/100) for E309L-16; for welding the order is ER70S-2 first (excellent, 98/100) then E309L-16 (excellent, 90/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E309L-16 and ER70S-2 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.