FabDigit

Steel ER309L vs ER70S-6 vs ER70S-3 vs ER70S-2

Benchmark · 4 materials

Side-by-side benchmark of 4 steel grades.

ER309L vs ER70S-6 and 2 more: properties

ER309LER70S-6ER70S-3ER70S-2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

196 GPa28.4 Msi
205 GPa29.7 Msi
205 GPa29.7 Msi
205 GPa29.7 Msi

Shear Modulus

77 GPa11.2 Msi
80 GPa11.6 Msi
79 GPa11.5 Msi
80 GPa11.6 Msi

Poisson's Ratio

0.28
0.29
0.29
0.29

Tensile Strength (Ultimate)

580 MPa84.1 ksi
560 MPa81.2 ksi
550 MPa79.8 ksi
560 MPa81.2 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
460 MPa66.7 ksi
460 MPa66.7 ksi
450 MPa65.3 ksi

Elongation at Break

38%
27%
28%
28%

Reduction in Area

55%
65%
65%
68%

Compressive Strength

410 MPa59.5 ksi
460 MPa66.7 ksi
460 MPa66.7 ksi
450 MPa65.3 ksi

Shear Strength

380 MPa55.1 ksi
340 MPa49.3 ksi
330 MPa47.9 ksi
345 MPa50 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
240 MPa34.8 ksi
230 MPa33.4 ksi
235 MPa34.1 ksi

Fracture Toughness (K_IC)

150 MPa·√m137 ksi·√in
120 MPa·√m109 ksi·√in
100 MPa·√m91 ksi·√in
115 MPa·√m105 ksi·√in

Charpy V-Notch Impact (RT)

75 J55.3 ft·lbf
130 J95.9 ft·lbf
90 J66.4 ft·lbf
120 J88.5 ft·lbf

Hardness, Brinell

185 HB
160 HB
160 HB
155 HB

Hardness, Rockwell B

90 HRB
84 HRB
84 HRB
82 HRB

Hardness, Rockwell C

11 HRC

Hardness, Vickers

195 HV
170 HV
168 HV
163 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Density

7.9 g/cm³0.29 lb/in³
7.85 g/cm³0.28 lb/in³
7.85 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
1,470°C2,678 °F
1,470°C2,678 °F

Liquidus Temperature

1,450°C2,642 °F
1,520°C2,768 °F
1,520°C2,768 °F
1,520°C2,768 °F

Thermal

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

Thermal Conductivity

15.5 W/m·K9 BTU/hr·ft·°F
49 W/m·K28.3 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

15.5 µm/m·K8.6 µin/in·°F
12 µm/m·K6.7 µin/in·°F
12 µm/m·K6.7 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Latent Heat of Fusion

275 J/g118 BTU/lb
270 J/g116 BTU/lb
247 J/g106 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

1,000°C1,832 °F
400°C752 °F
400°C752 °F
400°C752 °F

Min Service Temperature

-196°C-321 °F
-30°C-22 °F
-30°C-22 °F
-30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.3 % IACS
10.5 % IACS
10 % IACS
10.5 % IACS

Electrical Resistivity

7.8×10⁻⁷ Ω·m30.7 µΩ·in
1.6×10⁻⁷ Ω·m6.3 µΩ·in
1.7×10⁻⁷ Ω·m6.69 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
-0.65 V
-0.65 V
-0.61 V

Corrosion Resistance

68 / 100
10 / 100
10 / 100
10 / 100

Manufacturability

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

Machinability

35 / 100
58 / 100
58 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
65%
60%
65%

Weldability

90 / 100
95 / 100
95 / 100
98 / 100

Formability (cold)

60 / 100
60 / 100
80 / 100
70 / 100

Brazeability / Solderability

55 / 100
65 / 100
70 / 100
65 / 100

Polishability

65 / 100
45 / 100
55 / 100
50 / 100

Castability

70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
28 MJ/kg12,038 BTU/lb
32 MJ/kg13,758 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

4.6 kg CO₂/kg
2.1 kg CO₂/kg
2.4 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
45 L/kg5.4 gal/lb
60 L/kg7.2 gal/lb
35 L/kg4.2 gal/lb

Typical Recycled Content

60%
25%
25%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

73 kN·m/kg
71 kN·m/kg
70 kN·m/kg
71 kN·m/kg

Specific Stiffness (E / density)

24.8 MN·m/kg
26.1 MN·m/kg
26.1 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

408 kJ/m³
516 kJ/m³
516 kJ/m³
494 kJ/m³

Thermal Diffusivity

3.9 mm²/s
13 mm²/s
13 mm²/s
13 mm²/s

Thermal Shock Resistance Index

3
11
11
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-6ER70S-3ER70S-2ER309L

Manufacturing and finishing

CapabilityER309LER70S-6ER70S-3ER70S-2
Default condition
Relative cost$$$$ High$ Budget$ Budget$$ 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.

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER309L and ER70S-6 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.