FabDigitFabDigit

Cobalt-Chrome Alloy L605 vs Phynox

Cobalt-Chrome Alloy · grade comparison

Cobalt-Chrome Alloy L605 and Phynox are both cobalt-chrome alloy grades. Phynox is the stronger of the two: yield strength 1,850 MPa (268 ksi) against 460 MPa (66.7 ksi) for L605, about 4.0 times as much; tensile strength follows at 2,050 MPa (297 ksi) vs 1,010 MPa (146 ksi). In exchange, L605 is the more ductile: elongation 58% versus 3% for Phynox, and Phynox is harder (630 HV vs 250 HV). Phynox is lighter (8.3 g/cm³ vs 9.13 g/cm³ for L605) and L605 runs hotter in service (980°C vs 400°C continuous). On the shop floor, L605 welds better (very good vs poor) and Phynox sits in a lower cost tier (high, $$$$) than L605 (specialty, $$$$$).

L605Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

PhynoxChoose it when strength drives the design, or when weight is the constraint.

L605 vs Phynox: properties

L605Phynox

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

225 GPa32.6 Msi
220 GPa31.9 Msi

Shear Modulus

87 GPa12.6 Msi
85 GPa12.3 Msi

Bulk Modulus

178 GPa25.8 Msi
175 GPa25.4 Msi

Tensile Strength (Ultimate)

1,010 MPa146 ksi
2,050 MPa297 ksi

Yield Strength (0.2% offset)

460 MPa66.7 ksi
1,850 MPa268 ksi

Elongation at Break

58%
3%

Reduction in Area

55%
—

Shear Strength

620 MPa89.9 ksi
1,200 MPa174 ksi

Fatigue Strength (Endurance Limit)

440 MPa63.8 ksi
800 MPa116 ksi

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
—

Hardness, Brinell

240 HB
—

Hardness, Rockwell B

98 HRB
—

Hardness, Vickers

250 HV
630 HV

Compressive Strength

—
1,900 MPa276 ksi

Hardness, Rockwell C

—
57 HRC

Same in both: Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

9.13 g/cm³0.33 lb/in³
8.3 g/cm³0.3 lb/in³

Melting Point (Solidus)

1,329°C2,424 °F
1,440°C2,624 °F

Liquidus Temperature

1,410°C2,570 °F
1,495°C2,723 °F

Thermal

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

Thermal Conductivity

9.4 W/m·K5.4 BTU/hr·ft·°F
12.6 W/m·K7.3 BTU/hr·ft·°F

Specific Heat Capacity

385 J/kg·K0.09 BTU/lb·°F
430 J/kg·K0.1 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12.3 µm/m·K6.8 µin/in·°F
13.5 µm/m·K7.5 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
—

Max Service Temperature (continuous)

980°C1,796 °F
400°C752 °F

Same in both: Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

1.9 % IACS
1.7 % IACS

Electrical Resistivity

8.9×10⁻⁷ Ω·m35 µΩ·in
1.02×10⁻⁶ Ω·m40.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.25 V
-0.2 V

Corrosion Resistance

82 / 100
85 / 100

Manufacturability

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

Machinability

18 / 100
10 / 100

Machinability Rating (AISI 1212 = 100 %)

12%
8%

Weldability

72 / 100
30 / 100

Formability (cold)

60 / 100
15 / 100

Castability

55 / 100
—

Brazeability / Solderability

70 / 100
45 / 100

Polishability

80 / 100
85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

250 MJ/kg107,481 BTU/lb
130 MJ/kg55,890 BTU/lb

Embodied Carbon (primary production)

19 kg CO₂/kg
9.5 kg CO₂/kg

Embodied Water

500 L/kg59.9 gal/lb
—

Typical Recycled Content

30%
20%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

111 kN·m/kg
247 kN·m/kg

Specific Stiffness (E / density)

24.6 MN·m/kg
26.5 MN·m/kg

Modulus of Resilience

470 kJ/m³
7,778 kJ/m³

Thermal Diffusivity

2.7 mm²/s
3.5 mm²/s

Thermal Shock Resistance Index

3
9

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 scaleL605Phynox

Manufacturing and finishing

CapabilityL605Phynox
CNC machiningYes—
Default conditionSolution Annealed—
Relative cost$$$$$ Specialty$$$$ High
Min. machined wall——
Best machined surface——
ElectropolishingYes—
Passivation (Stainless Steel)Yes—

L605 vs Phynox — frequently asked

Is Phynox stronger than L605?

Yes. Phynox has a typical yield strength of 1,850 MPa (268 ksi) against 460 MPa (66.7 ksi) for L605 — about 4.0 times as much. Tensile strength is 2,050 MPa (297 ksi) vs 1,010 MPa (146 ksi).

Which is cheaper, L605 or Phynox?

Phynox is the lower-cost material: it sits in the high tier ($$$$) while L605 is specialty ($$$$$). 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, L605 or Phynox?

L605. Its machinability rates poor (18/100) against not recommended (10/100) for Phynox; for welding the order is L605 first (very good, 72/100) then Phynox (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in L605 and Phynox 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.