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Cobalt-Chrome Alloy ERCoCr-A vs Stellite 6

Cobalt-Chrome Alloy · grade comparison

Cobalt-Chrome Alloy ERCoCr-A and Stellite 6 are both cobalt-chrome alloy grades. ERCoCr-A is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 541 MPa (78.5 ksi) for Stellite 6, about 15% more. On the shop floor, ERCoCr-A sits in a lower cost tier (high, $$$$) than Stellite 6 (specialty, $$$$$).

ERCoCr-AChoose it when strength drives the design, or when cost is the deciding factor.

ERCoCr-A vs Stellite 6: properties

ERCoCr-AStellite 6

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
220 GPa31.9 Msi

Shear Modulus

81 GPa11.7 Msi
85 GPa12.3 Msi

Bulk Modulus

175 GPa25.4 Msi
180 GPa26.1 Msi

Tensile Strength (Ultimate)

830 MPa120 ksi
834 MPa121 ksi

Yield Strength (0.2% offset)

620 MPa89.9 ksi
541 MPa78.5 ksi

Compressive Strength

1,500 MPa218 ksi
1,450 MPa210 ksi

Shear Strength

540 MPa78.3 ksi
—

Fatigue Strength (Endurance Limit)

270 MPa39.2 ksi
275 MPa39.9 ksi

Fracture Toughness (K_IC)

35 MPa·√m31.9 ksi·√in
25 MPa·√m22.8 ksi·√in

Charpy V-Notch Impact (RT)

8 J5.9 ft·lbf
5 J3.7 ft·lbf

Hardness, Brinell

390 HB
—

Hardness, Rockwell C

41 HRC
40 HRC

Hardness, Vickers

430 HV
425 HV

Same in both: Poisson's Ratio 0.3 · Elongation at Break 1%

Physical

Density and transition temperatures.

Same in both: Density 8.44 g/cm³0.3 lb/in³ · Melting Point (Solidus) 1,285°C2,345 °F · Liquidus Temperature 1,395°C2,543 °F

Thermal

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

Thermal Expansion (CTE, 20–100 °C)

12 µm/m·K6.7 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Same in both: Thermal Conductivity 14.8 W/m·K8.6 BTU/hr·ft·°F · Specific Heat Capacity 423 J/kg·K0.1 BTU/lb·°F · Max Service Temperature (continuous) 800°C1,472 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2 % IACS
1.9 % IACS

Electrical Resistivity

8.8×10⁻⁷ Ω·m34.6 µΩ·in
9×10⁻⁷ Ω·m35.4 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

78 / 100
70 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.25 V

Manufacturability

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

Formability (cold)

3 / 100
5 / 100

Polishability

80 / 100
85 / 100

Same in both: Machinability 8 / 100 · Machinability Rating (AISI 1212 = 100 %) 5% · Weldability 55 / 100 · Castability 70 / 100 · Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

155 MJ/kg66,638 BTU/lb
150 MJ/kg64,488 BTU/lb

Embodied Carbon (primary production)

11.5 kg CO₂/kg
13 kg CO₂/kg

Embodied Water

350 L/kg41.9 gal/lb
400 L/kg47.9 gal/lb

Typical Recycled Content

25%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

98 kN·m/kg
99 kN·m/kg

Specific Stiffness (E / density)

24.9 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

915 kJ/m³
665 kJ/m³

Thermal Shock Resistance Index

5
4

Same in both: Thermal Diffusivity 4.1 mm²/s

Strength versus weight

Yield strength against density for every cobalt-chrome alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

5007001,0001,5002,0008.28.48.68.89Density (g/cm³)Yield strength (MPa) — log scaleStellite 6ERCoCr-A

Manufacturing and finishing

CapabilityERCoCr-AStellite 6
Default condition—As Cast
Relative cost$$$$ High$$$$$ Specialty
Min. machined wall——
Best machined surface——

ERCoCr-A vs Stellite 6 — frequently asked

Is ERCoCr-A stronger than Stellite 6?

Yes. ERCoCr-A has a typical yield strength of 620 MPa (89.9 ksi) against 541 MPa (78.5 ksi) for Stellite 6 — about 15% more. Tensile strength is 830 MPa (120 ksi) vs 834 MPa (121 ksi).

Which is cheaper, ERCoCr-A or Stellite 6?

ERCoCr-A is the lower-cost material: it sits in the high tier ($$$$) while Stellite 6 is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

When should I choose ERCoCr-A over Stellite 6?

Pick ERCoCr-A when strength drives the design, or when cost is the deciding factor.

Ready to make it?

Upload a CAD file and FabDigit prices the part in ERCoCr-A and Stellite 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.