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Steel E90C-K3 vs ER70S-6

Steel · grade comparison

Steel E90C-K3 and ER70S-6 are both steel grades. E90C-K3 is the stronger of the two: yield strength 610 MPa (88.5 ksi) against 460 MPa (66.7 ksi) for ER70S-6, about 33% more; tensile strength follows at 690 MPa (100 ksi) vs 560 MPa (81.2 ksi). In exchange, ER70S-6 is the more ductile: elongation 27% versus 22% for E90C-K3, and E90C-K3 is harder (220 HB vs 160 HB). ER70S-6 conducts heat better (49 W/m·K vs 38 W/m·K). On the shop floor, ER70S-6 machines more easily (good vs fair), ER70S-6 welds better (excellent vs very good), and ER70S-6 sits in a lower cost tier (budget, $) than E90C-K3 (standard, $$).

E90C-K3Choose it when strength drives the design.

ER70S-6Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

E90C-K3 vs ER70S-6: properties

E90C-K3ER70S-6

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

690 MPa100 ksi
560 MPa81.2 ksi

Yield Strength (0.2% offset)

610 MPa88.5 ksi
460 MPa66.7 ksi

Elongation at Break

22%
27%

Reduction in Area

60%
65%

Shear Strength

410 MPa59.5 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
120 MPa·√m109 ksi·√in

Charpy V-Notch Impact (RT)

110 J81.1 ft·lbf
130 J95.9 ft·lbf

Hardness, Brinell

220 HB
160 HB

Hardness, Rockwell C

20 HRC
—

Hardness, Vickers

230 HV
170 HV

Compressive Strength

—
460 MPa66.7 ksi

Hardness, Rockwell B

—
84 HRB

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)

1,450°C2,642 °F
1,470°C2,678 °F

Liquidus Temperature

1,505°C2,741 °F
1,520°C2,768 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

38 W/m·K22 BTU/hr·ft·°F
49 W/m·K28.3 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Min Service Temperature

-50°C-58 °F
-30°C-22 °F

Same in both: Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
10.5 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 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)

-0.62 V
-0.65 V

Corrosion Resistance

15 / 100
10 / 100

Manufacturability

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

Machinability

40 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
65%

Weldability

80 / 100
95 / 100

Formability (cold)

35 / 100
60 / 100

Brazeability / Solderability

55 / 100
65 / 100

Polishability

55 / 100
45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
28 MJ/kg12,038 BTU/lb

Embodied Carbon (primary production)

2.4 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

88 kN·m/kg
71 kN·m/kg

Modulus of Resilience

908 kJ/m³
516 kJ/m³

Thermal Diffusivity

10.3 mm²/s
13 mm²/s

Thermal Shock Resistance Index

10
11

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-6E90C-K3

Manufacturing and finishing

CapabilityE90C-K3ER70S-6
Default condition——
Relative cost$$ Standard$ Budget
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.

E90C-K3 vs ER70S-6 — frequently asked

Is E90C-K3 stronger than ER70S-6?

Yes. E90C-K3 has a typical yield strength of 610 MPa (88.5 ksi) against 460 MPa (66.7 ksi) for ER70S-6 — about 33% more. Tensile strength is 690 MPa (100 ksi) vs 560 MPa (81.2 ksi).

Which is cheaper, E90C-K3 or ER70S-6?

ER70S-6 is the lower-cost material: it sits in the budget tier ($) while E90C-K3 is standard ($$). 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, E90C-K3 or ER70S-6?

ER70S-6. Its machinability rates good (58/100) against fair (40/100) for E90C-K3; for welding the order is ER70S-6 first (excellent, 95/100) then E90C-K3 (very good, 80/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E90C-K3 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.