FabDigitFabDigit

Steel ER316L vs ER70S-2

Steel · grade comparison

Steel ER316L and ER70S-2 are both steel grades. ER70S-2 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 420 MPa (60.9 ksi) for ER316L, about 7% more. In exchange, ER316L is the more ductile: elongation 40% versus 28% for ER70S-2, and ER316L is harder (175 HB vs 155 HB). ER316L runs hotter in service (550°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, $$) than ER316L (premium, $$$).

ER316LChoose 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.

ER316L vs ER70S-2: properties

ER316LER70S-2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

195 GPa28.3 Msi
205 GPa29.7 Msi

Shear Modulus

77 GPa11.2 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

570 MPa82.7 ksi
560 MPa81.2 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
450 MPa65.3 ksi

Elongation at Break

40%
28%

Reduction in Area

55%
68%

Compressive Strength

420 MPa60.9 ksi
450 MPa65.3 ksi

Shear Strength

400 MPa58 ksi
345 MPa50 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
235 MPa34.1 ksi

Fracture Toughness (K_IC)

150 MPa·√m137 ksi·√in
115 MPa·√m105 ksi·√in

Charpy V-Notch Impact (RT)

100 J73.8 ft·lbf
120 J88.5 ft·lbf

Hardness, Brinell

175 HB
155 HB

Hardness, Rockwell B

88 HRB
82 HRB

Hardness, Rockwell C

9 HRC
—

Hardness, Vickers

185 HV
163 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

7.98 g/cm³0.29 lb/in³
7.85 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,385°C2,525 °F
1,470°C2,678 °F

Liquidus Temperature

1,425°C2,597 °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

Max Service Temperature (continuous)

550°C1,022 °F
400°C752 °F

Min Service Temperature

-196°C-321 °F
-30°C-22 °F

Same in both: Latent Heat of Fusion 270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

2.3 % IACS
10.5 % IACS

Electrical Resistivity

7.5×10⁻⁷ Ω·m29.5 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)

-0.08 V
-0.61 V

Corrosion Resistance

72 / 100
10 / 100

Manufacturability

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

Machinability

36 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

38%
65%

Weldability

90 / 100
98 / 100

Formability (cold)

68 / 100
70 / 100

Castability

55 / 100
—

Brazeability / Solderability

60 / 100
65 / 100

Polishability

70 / 100
50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

72 MJ/kg30,954 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

5.5 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

200 L/kg24 gal/lb
35 L/kg4.2 gal/lb

Typical Recycled Content

55%
25%

Common Calculations

Ratios derived from the values above.

Specific Stiffness (E / density)

24.4 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

452 kJ/m³
494 kJ/m³

Thermal Diffusivity

3.8 mm²/s
13 mm²/s

Thermal Shock Resistance Index

3
10

Same in both: Specific Strength (UTS / density) 71 kN·m/kg

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-2ER316L

Manufacturing and finishing

CapabilityER316LER70S-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.

ER316L vs ER70S-2 — frequently asked

Is ER70S-2 stronger than ER316L?

Yes. ER70S-2 has a typical yield strength of 450 MPa (65.3 ksi) against 420 MPa (60.9 ksi) for ER316L — about 7% more. Tensile strength is 560 MPa (81.2 ksi) vs 570 MPa (82.7 ksi).

Which is cheaper, ER316L or ER70S-2?

ER70S-2 is the lower-cost material: it sits in the standard tier ($$) while ER316L is premium ($$$). 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, ER316L or ER70S-2?

ER70S-2. Its machinability rates good (62/100) against fair (36/100) for ER316L; for welding the order is ER70S-2 first (excellent, 98/100) then ER316L (excellent, 90/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER316L 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.