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Steel ER70S-2 vs ER80S-B8

Steel · grade comparison

Steel ER70S-2 and ER80S-B8 are both steel grades. ER80S-B8 is the stronger of the two: yield strength 490 MPa (71.1 ksi) against 450 MPa (65.3 ksi) for ER70S-2, about 9% more; tensile strength follows at 620 MPa (89.9 ksi) vs 560 MPa (81.2 ksi). In exchange, ER70S-2 is the more ductile: elongation 28% versus 22% for ER80S-B8, and ER80S-B8 is harder (200 HB vs 155 HB). ER80S-B8 runs hotter in service (600°C vs 400°C continuous) and ER70S-2 conducts heat better (48 W/m·K vs 28 W/m·K). On the shop floor, ER70S-2 machines more easily (good vs fair), ER70S-2 welds better (excellent vs good), and ER70S-2 sits in a lower cost tier (standard, $$) than ER80S-B8 (high, $$$$).

ER70S-2Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

ER80S-B8Choose it when strength drives the design, or when the part sees heat.

ER70S-2 vs ER80S-B8: properties

ER70S-2ER80S-B8

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
210 GPa30.5 Msi

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Tensile Strength (Ultimate)

560 MPa81.2 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
490 MPa71.1 ksi

Elongation at Break

28%
22%

Reduction in Area

68%
55%

Compressive Strength

450 MPa65.3 ksi
—

Shear Strength

345 MPa50 ksi
390 MPa56.6 ksi

Fatigue Strength (Endurance Limit)

235 MPa34.1 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

115 MPa·√m105 ksi·√in
90 MPa·√m81.9 ksi·√in

Charpy V-Notch Impact (RT)

120 J88.5 ft·lbf
65 J47.9 ft·lbf

Hardness, Brinell

155 HB
200 HB

Hardness, Rockwell B

82 HRB
—

Hardness, Vickers

163 HV
210 HV

Hardness, Rockwell C

—
16 HRC

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

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,470°C2,678 °F
1,420°C2,588 °F

Liquidus Temperature

1,520°C2,768 °F
1,480°C2,696 °F

Thermal

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

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
28 W/m·K16.2 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

12.5 µm/m·K6.9 µin/in·°F
11.5 µm/m·K6.4 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
600°C1,112 °F

Min Service Temperature

-30°C-22 °F
-20°C-4 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

10.5 % IACS
3 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
5.7×10⁻⁷ Ω·m22.4 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
—

Corrosion Resistance

10 / 100
32 / 100

Manufacturability

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

Machinability

62 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
50%

Weldability

98 / 100
55 / 100

Formability (cold)

70 / 100
45 / 100

Brazeability / Solderability

65 / 100
55 / 100

Polishability

50 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
34 MJ/kg14,617 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.6 kg CO₂/kg

Embodied Water

35 L/kg4.2 gal/lb
60 L/kg7.2 gal/lb

Typical Recycled Content

25%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

71 kN·m/kg
80 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
27.1 MN·m/kg

Modulus of Resilience

494 kJ/m³
572 kJ/m³

Thermal Diffusivity

13 mm²/s
7.7 mm²/s

Thermal Shock Resistance Index

10
7

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-2ER80S-B8

Manufacturing and finishing

CapabilityER70S-2ER80S-B8
Default condition——
Relative cost$$ Standard$$$$ High
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-2 vs ER80S-B8 — frequently asked

Is ER80S-B8 stronger than ER70S-2?

Yes. ER80S-B8 has a typical yield strength of 490 MPa (71.1 ksi) against 450 MPa (65.3 ksi) for ER70S-2 — about 9% more. Tensile strength is 620 MPa (89.9 ksi) vs 560 MPa (81.2 ksi).

Which is cheaper, ER70S-2 or ER80S-B8?

ER70S-2 is the lower-cost material: it sits in the standard tier ($$) while ER80S-B8 is high ($$$$). 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, ER70S-2 or ER80S-B8?

ER70S-2. Its machinability rates good (62/100) against fair (38/100) for ER80S-B8; for welding the order is ER70S-2 first (excellent, 98/100) then ER80S-B8 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER70S-2 and ER80S-B8 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.