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Steel ER70S-3 vs ER70S-B2L

Steel · grade comparison

Steel ER70S-3 and ER70S-B2L are both steel grades. ER70S-B2L is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 460 MPa (66.7 ksi) for ER70S-3, about 13% more; tensile strength follows at 620 MPa (89.9 ksi) vs 550 MPa (79.8 ksi). In exchange, ER70S-3 is the more ductile: elongation 28% versus 22% for ER70S-B2L, and ER70S-B2L is harder (205 HB vs 160 HB). ER70S-B2L runs hotter in service (450°C vs 400°C continuous) and ER70S-3 conducts heat better (48 W/m·K vs 42 W/m·K). On the shop floor, ER70S-3 welds better (excellent vs very good) and ER70S-3 sits in a lower cost tier (budget, $) than ER70S-B2L (premium, $$$).

ER70S-3Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

ER70S-B2LChoose it when strength drives the design, or when the part sees heat.

ER70S-3 vs ER70S-B2L: properties

ER70S-3ER70S-B2L

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

79 GPa11.5 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

550 MPa79.8 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

460 MPa66.7 ksi
520 MPa75.4 ksi

Elongation at Break

28%
22%

Reduction in Area

65%
60%

Compressive Strength

460 MPa66.7 ksi
—

Shear Strength

330 MPa47.9 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
270 MPa39.2 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
—

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
80 J59 ft·lbf

Hardness, Brinell

160 HB
205 HB

Hardness, Rockwell B

84 HRB
95 HRB

Hardness, Vickers

168 HV
215 HV

Hardness, Rockwell C

—
18 HRC

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,470°C2,678 °F
1,490°C2,714 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,520°C2,768 °F

Thermal

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

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12 µm/m·K6.7 µin/in·°F
12.3 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

400°C752 °F
450°C842 °F

Same in both: Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
8 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.65 V
-0.6 V

Corrosion Resistance

10 / 100
18 / 100

Manufacturability

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

Machinability

58 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
50%

Weldability

95 / 100
75 / 100

Formability (cold)

80 / 100
45 / 100

Castability

70 / 100
—

Brazeability / Solderability

70 / 100
60 / 100

Same in both: Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
36 MJ/kg15,477 BTU/lb

Embodied Carbon (primary production)

2.4 kg CO₂/kg
2.8 kg CO₂/kg

Typical Recycled Content

25%
35%

Same in both: Embodied Water 60 L/kg7.2 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

70 kN·m/kg
79 kN·m/kg

Modulus of Resilience

516 kJ/m³
660 kJ/m³

Thermal Diffusivity

13 mm²/s
11.6 mm²/s

Thermal Shock Resistance Index

11
10

Same in both: Specific Stiffness (E / density) 26.1 MN·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-3ER70S-B2L

Manufacturing and finishing

CapabilityER70S-3ER70S-B2L
Default condition——
Relative cost$ Budget$$$ Premium
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.

ER70S-3 vs ER70S-B2L — frequently asked

Is ER70S-B2L stronger than ER70S-3?

Yes. ER70S-B2L has a typical yield strength of 520 MPa (75.4 ksi) against 460 MPa (66.7 ksi) for ER70S-3 — about 13% more. Tensile strength is 620 MPa (89.9 ksi) vs 550 MPa (79.8 ksi).

Which is cheaper, ER70S-3 or ER70S-B2L?

ER70S-3 is the lower-cost material: it sits in the budget tier ($) while ER70S-B2L 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, ER70S-3 or ER70S-B2L?

ER70S-3. Its machinability rates good (58/100) against fair (50/100) for ER70S-B2L; for welding the order is ER70S-3 first (excellent, 95/100) then ER70S-B2L (very good, 75/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER70S-3 and ER70S-B2L 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.