UNS R30035 (2.4999) Co-Ni-Cr-Mo Alloy
R30035 cobalt is a cobalt alloy. It has a moderately low electrical conductivity among cobalt alloys. In addition, it has a moderately high embodied energy and a moderately low thermal conductivity.
The properties of R30035 cobalt include three common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare R30035 cobalt to other cobalt alloys (top) and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
220 to 230 GPa 31 to 34 x 106 psi
Elongation at Break
9.0 to 46 %
Fatigue Strength
170 to 740 MPa 25 to 110 x 103 psi
Poisson's Ratio
0.29
Reduction in Area
40 to 74 %
Shear Modulus
84 to 89 GPa 12 to 13 x 106 psi
Tensile Strength: Ultimate (UTS)
900 to 1900 MPa 130 to 280 x 103 psi
Tensile Strength: Yield (Proof)
300 to 1650 MPa 44 to 240 x 103 psi
Thermal Properties
Latent Heat of Fusion
320 J/g
Melting Completion (Liquidus)
1440 °C 2620 °F
Melting Onset (Solidus)
1320 °C 2400 °F
Specific Heat Capacity
440 J/kg-K 0.1 BTU/lb-°F
Thermal Conductivity
11 W/m-K 6.5 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
1.7 % IACS
Electrical Conductivity: Equal Weight (Specific)
1.8 % IACS
Otherwise Unclassified Properties
Base Metal Price
100 % relative
Density
8.7 g/cm3 540 lb/ft3
Embodied Carbon
10 kg CO2/kg material
Embodied Energy
140 MJ/kg 59 x 103 BTU/lb
Embodied Water
410 L/kg 49 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
160 to 320 MJ/m3
Resilience: Unit (Modulus of Resilience)
210 to 5920 kJ/m3
Stiffness to Weight: Axial
14 to 15 points
Stiffness to Weight: Bending
23 to 24 points
Strength to Weight: Axial
29 to 61 points
Strength to Weight: Bending
24 to 39 points
Thermal Diffusivity
3.0 mm2/s
Thermal Shock Resistance
23 to 46 points
Alloy Composition
| Ni | 33 to 37 | |
| Co | 29.1 to 39 | |
| Cr | 19 to 21 | |
| Mo | 9.0 to 10.5 | |
| Fe | 0 to 1.0 | |
| Ti | 0 to 1.0 | |
| Mn | 0 to 0.15 | |
| Si | 0 to 0.15 | |
| C | 0 to 0.025 | |
| P | 0 to 0.015 | |
| B | 0 to 0.015 | |
| S | 0 to 0.010 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
ASTM F688: Standard Specification for Wrought Cobalt-35 Nickel-20 Chromium-10 Molybdenum Alloy Plate, Sheet, and Foil for Surgical Implants (UNS R30035)
ASTM F562: Standard Specification for Wrought 35Cobalt-35Nickel-20Chromium-10Molybdenum Alloy for Surgical Implant Applications (UNS R30035)
ASTM F961: Standard Specification for 35Cobalt-35Nickel-20Chromium-10Molybdenum Alloy Forgings for Surgical Implants (UNS R30035)
ISO 5832-6: Implants for Surgery - Metallic Materials - Part 6: Wrought Cobalt-Nickel-Chromium-Molybdenum Alloy
ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys, Joseph R. Davis (editor), 2000