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Steel ER310 vs ER70S-2

Steel · grade comparison

Steel ER310 and ER70S-2 are both steel grades. ER70S-2 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 380 MPa (55.1 ksi) for ER310, about 18% more. In exchange, ER310 is the more ductile: elongation 35% versus 28% for ER70S-2, and ER310 is harder (180 HB vs 155 HB). ER310 runs hotter in service (1,050°C vs 400°C continuous) and ER70S-2 conducts heat better (48 W/m·K vs 14.2 W/m·K). On the shop floor, ER70S-2 machines more easily (good vs poor), ER70S-2 welds better (excellent vs good), and ER70S-2 sits in a lower cost tier (standard, $$) than ER310 (high, $$$$).

ER310Choose 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.

ER310 vs ER70S-2: properties

ER310ER70S-2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
205 GPa29.7 Msi

Shear Modulus

77 GPa11.2 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

590 MPa85.6 ksi
560 MPa81.2 ksi

Yield Strength (0.2% offset)

380 MPa55.1 ksi
450 MPa65.3 ksi

Elongation at Break

35%
28%

Reduction in Area

50%
68%

Compressive Strength

385 MPa55.8 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)

160 MPa·√m146 ksi·√in
115 MPa·√m105 ksi·√in

Charpy V-Notch Impact (RT)

80 J59 ft·lbf
120 J88.5 ft·lbf

Hardness, Brinell

180 HB
155 HB

Hardness, Rockwell B

89 HRB
82 HRB

Hardness, Vickers

190 HV
163 HV

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

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,400°C2,552 °F
1,470°C2,678 °F

Liquidus Temperature

1,450°C2,642 °F
1,520°C2,768 °F

Thermal

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

Thermal Conductivity

14.2 W/m·K8.2 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)

15.9 µm/m·K8.8 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Max Service Temperature (continuous)

1,050°C1,922 °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

2.2 % IACS
10.5 % IACS

Electrical Resistivity

7.8×10⁻⁷ Ω·m30.7 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

62 / 100
10 / 100

Manufacturability

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

Machinability

30 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
65%

Weldability

55 / 100
98 / 100

Formability (cold)

55 / 100
70 / 100

Castability

55 / 100
—

Brazeability / Solderability

55 / 100
65 / 100

Polishability

65 / 100
50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

76 MJ/kg32,674 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

5.6 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

210 L/kg25.2 gal/lb
35 L/kg4.2 gal/lb

Typical Recycled Content

55%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

75 kN·m/kg
71 kN·m/kg

Specific Stiffness (E / density)

25.3 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

361 kJ/m³
494 kJ/m³

Thermal Diffusivity

3.6 mm²/s
13 mm²/s

Thermal Shock Resistance Index

3
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-2ER310

Manufacturing and finishing

CapabilityER310ER70S-2
Default condition——
Relative cost$$$$ High$$ 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.

ER310 vs ER70S-2 — frequently asked

Is ER70S-2 stronger than ER310?

Yes. ER70S-2 has a typical yield strength of 450 MPa (65.3 ksi) against 380 MPa (55.1 ksi) for ER310 — about 18% more. Tensile strength is 560 MPa (81.2 ksi) vs 590 MPa (85.6 ksi).

Which is cheaper, ER310 or ER70S-2?

ER70S-2 is the lower-cost material: it sits in the standard tier ($$) while ER310 is high ($$$$). 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, ER310 or ER70S-2?

ER70S-2. Its machinability rates good (62/100) against poor (30/100) for ER310; for welding the order is ER70S-2 first (excellent, 98/100) then ER310 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER310 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.