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Steel ER70S-2 vs ER70S-A1

Steel · grade comparison

Steel ER70S-2 and ER70S-A1 are both steel grades. ER70S-A1 is the stronger of the two: yield strength 500 MPa (72.5 ksi) against 450 MPa (65.3 ksi) for ER70S-2, about 11% more; tensile strength follows at 590 MPa (85.6 ksi) vs 560 MPa (81.2 ksi). In exchange, ER70S-2 is the more ductile: elongation 28% versus 25% for ER70S-A1, and ER70S-A1 is harder (185 HB vs 155 HB). ER70S-A1 runs hotter in service (450°C vs 400°C continuous) and ER70S-2 conducts heat better (48 W/m·K vs 41 W/m·K). On the shop floor, ER70S-2 machines more easily (good vs fair) and ER70S-2 welds better (98 vs 88 out of 100).

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

ER70S-A1Choose it when strength drives the design, or when the part sees heat.

ER70S-2 vs ER70S-A1: properties

ER70S-2ER70S-A1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

560 MPa81.2 ksi
590 MPa85.6 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
500 MPa72.5 ksi

Elongation at Break

28%
25%

Reduction in Area

68%
58%

Compressive Strength

450 MPa65.3 ksi
505 MPa73.2 ksi

Shear Strength

345 MPa50 ksi
360 MPa52.2 ksi

Fatigue Strength (Endurance Limit)

235 MPa34.1 ksi
255 MPa37 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
80 J59 ft·lbf

Hardness, Brinell

155 HB
185 HB

Hardness, Rockwell B

82 HRB
90 HRB

Hardness, Vickers

163 HV
195 HV

Hardness, Rockwell C

—
12 HRC

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 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
1,460°C2,660 °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
41 W/m·K23.7 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

12.5 µm/m·K6.9 µin/in·°F
12.3 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
450°C842 °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

Electrical

Conductivity and insulation.

Electrical Conductivity

10.5 % IACS
8.5 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
2.05×10⁻⁷ Ω·m8.07 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.65 V

Corrosion Resistance

10 / 100
13 / 100

Manufacturability

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

Machinability

62 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
55%

Weldability

98 / 100
88 / 100

Formability (cold)

70 / 100
50 / 100

Brazeability / Solderability

65 / 100
60 / 100

Same in both: Polishability 50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

35 L/kg4.2 gal/lb
45 L/kg5.4 gal/lb

Same in both: Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

71 kN·m/kg
75 kN·m/kg

Modulus of Resilience

494 kJ/m³
610 kJ/m³

Thermal Diffusivity

13 mm²/s
11.1 mm²/s

Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg · Thermal Shock Resistance Index 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-2ER70S-A1

Manufacturing and finishing

CapabilityER70S-2ER70S-A1
Default condition——
Relative cost$$ Standard$$ 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.

ER70S-2 vs ER70S-A1 — frequently asked

Is ER70S-A1 stronger than ER70S-2?

Yes. ER70S-A1 has a typical yield strength of 500 MPa (72.5 ksi) against 450 MPa (65.3 ksi) for ER70S-2 — about 11% more. Tensile strength is 590 MPa (85.6 ksi) vs 560 MPa (81.2 ksi).

Which is cheaper, ER70S-2 or ER70S-A1?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, ER70S-2 or ER70S-A1?

ER70S-2. Its machinability rates good (62/100) against fair (52/100) for ER70S-A1; for welding the order is ER70S-2 first (excellent, 98/100) then ER70S-A1 (excellent, 88/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER70S-2 and ER70S-A1 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.