Cobalt-Chrome Alloy Phynox
UNS R30008
Phynox is an Elgiloy-family Co-Cr-Ni-Mo spring alloy (UNS R30008) supplied annealed, half-hard, cold-worked and cold-worked-plus-aged.
Reference datasheet — Phynox is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the CW+A condition
Phynox tempers and conditions
Phynox is supplied in 4 conditions, soft to hard. CW+A is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Pick for deep drawing, deep bending or machining before final cold work/ageing. | 450 | 950 | 55 | 26 HRC | — |
1/2 Hard | Compromise temper for parts needing some bending or forming yet moderate spring strength. | 1,250 | 1,450 | 10 | 45 HRC | 1.8 % IACS |
Cold worked | Standard as-supplied strip/wire condition for coiling and stamping springs that will be aged afterwards. | 1,600 | 1,800 | 5 | 52 HRC | — |
CW+ADefault Cold worked and age hardened | Final high-strength spring/stent condition: maximum strength, fatigue life and relaxation resistance after forming. | 1,850 | 2,050 | 3 | 57 HRC | — |
What is Phynox?
Phynox is an Elgiloy-family Co-Cr-Ni-Mo spring alloy (UNS R30008) supplied annealed, half-hard, cold-worked and cold-worked-plus-aged. Cold work plus ageing gives about 1850 MPa yield, 2050 MPa tensile, 57 HRC and 220 GPa modulus with high fatigue strength, biocompatibility and a corrosion resistance rating of 85, so it is drawn into fine wire, tube and strip for implantable springs and stents. Elongation is 3 %, machinability and formability are low, welding removes the cold-work strengthening locally, and service is limited to 400 °C. Elgiloy is the nearest equivalent. Phynox has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of cobalt-chrome alloy grades. It melts at 1,440°C (2,624 °F). Phynox has a yield strength of 1,850 MPa (268 ksi) and a tensile strength of 2,050 MPa (297 ksi) — stronger than 96% of cobalt-chrome alloy grades. Elongation at break is 3% and the elastic modulus is 220 GPa (31.9 Msi).
What is Phynox used for?
- coronary stents
- surgical springs
- guidewires
Advantages
- High strength — 1,850 MPa (268 ksi), better than 96% of cobalt-chrome alloy grades
- Low embodied carbon — 9.5 kg CO₂/kg, better than 87% of cobalt-chrome alloy grades
Limitations
- Limited service temperature — 400°C (752 °F), worse than 96% of cobalt-chrome alloy grades
Phynox properties
Typical room-temperature values for Phynox-CW+A; bars are the position among cobalt-chrome alloy grades.
Physical3
Phynox has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of cobalt-chrome alloy grades. It melts at 1,440°C (2,624 °F).
Mechanical12
Phynox has a yield strength of 1,850 MPa (268 ksi) and a tensile strength of 2,050 MPa (297 ksi) — stronger than 96% of cobalt-chrome alloy grades. Elongation at break is 3% and the elastic modulus is 220 GPa (31.9 Msi).
Thermal5
Phynox is rated for continuous service to 400°C (752 °F). It conducts heat at 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 71% of cobalt-chrome alloy grades. Thermal expansion is 13.5 µm/m·K (7.5 µin/in·°F).
Electrical3
Phynox conducts electricity at 1.7 % IACS, worse than 92% of cobalt-chrome alloy grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 79% of cobalt-chrome alloy grades.
Sustainability3
Producing a kilogram of Phynox takes about 130 MJ of energy and emits 9.5 kg of CO₂ — less than 89% of cobalt-chrome alloy grades. Typical recycled content is 20%.
Manufacturability7
Phynox's machinability is not recommended (10/100, better than 52% of cobalt-chrome alloy grades); weldability poor (30/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the cobalt-chrome alloy family
Yield strength against density for every cobalt-chrome alloy grade FabDigit runs. Phynox is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Phynox
Is Phynox easy to machine?
Very difficult and highly work-hardening — machine in the annealed condition with rigid setups, positive-rake carbide or ceramic tooling, low speed, heavy feed and flood coolant; grinding/EDM preferred for aged parts.
Can Phynox be welded?
Resistance, micro-TIG and laser welding are used for medical assemblies; filler-free autogenous joints are best, and any weld locally destroys the cold-work/ageing strengthening, so re-age or design joints out of high-stress zones.
Can Phynox be formed, bent or molded?
Coil, stamp or bend in the annealed or spring temper, then age 500–550 °C for 4–5 h to reach full strength; allow for springback and use generous bend radii on cold-worked stock.
Phynox chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Co | 39 – 41 | 40 |
| Cr | 19 – 21 | 20 |
| Ni | 14 – 18 | 16 |
| Mo | 6.5 – 7.5 | 7 |
| Mn | 1.5 – 2.5 | 2 |
| C | ≤ 0.15 | 0.1 |
| Beberyllium-free grade (unlike F1058 Grade 1 / Elgiloy) | ≤ 0 | 0 |
| Si | ≤ 1.2 | 0.3 |
| P | ≤ 0.02 | |
| S | ≤ 0.02 | |
| Febalance, typically ≈15 % | balance |
What surface finishes work on Phynox?
Electropolishing and passivation give the bright, low-inclusion medical surface; mechanical polishing to mirror finish is easy, PVD or gold plating is possible, anodising is not applicable.
Equivalent designations
Standards and trade names that resolve to Cobalt-Chrome Alloy Phynox in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R30008
- Also called
- F1058 Grade 2
How much does Phynox cost?
Phynox is a high-cost cobalt-chrome alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Phynox — frequently asked
What is Phynox used for?
Phynox is typically used for coronary stents, surgical springs and guidewires. In short: medical-grade cobalt spring alloy; biocompatible fatigue performance; fine wire and strip.
What is the yield strength of Phynox?
Phynox has a typical yield strength of 1,850 MPa (268 ksi) and a tensile strength of 2,050 MPa (297 ksi) — stronger than 96% of cobalt-chrome alloy grades. Strength varies by condition: see the 4 listed tempers.
Is Phynox easy to machine?
Not especially — machinability is rated not recommended (10/100, better than 52% of cobalt-chrome alloy grades). Very difficult and highly work-hardening — machine in the annealed condition with rigid setups, positive-rake carbide or ceramic tooling, low speed, heavy feed and flood coolant; grinding/EDM preferred for aged parts.
Can Phynox be welded?
Not readily — weldability is rated poor (30/100). Resistance, micro-TIG and laser welding are used for medical assemblies; filler-free autogenous joints are best, and any weld locally destroys the cold-work/ageing strengthening, so re-age or design joints out of high-stress zones.
What surface finishes work on Phynox?
Electropolishing and passivation give the bright, low-inclusion medical surface; mechanical polishing to mirror finish is easy, PVD or gold plating is possible, anodising is not applicable.
Can Phynox be formed, bent or molded?
Coil, stamp or bend in the annealed or spring temper, then age 500–550 °C for 4–5 h to reach full strength; allow for springback and use generous bend radii on cold-worked stock.
What is the maximum service temperature of Phynox?
Phynox is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Phynox CW+A and Phynox-A?
CW+A is the default condition — final high-strength spring/stent condition: maximum strength, fatigue life and relaxation resistance after forming. A: pick for deep drawing, deep bending or machining before final cold work/ageing. Yield strength is 1,850 MPa in CW+A versus 450 MPa in A.
How much does Phynox cost?
Phynox is a high-cost cobalt-chrome alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM F1058 — Wrought 40Co-20Cr-16Fe-15Ni-7Mo Alloy Wire and Strip for Surgical Implants — ASTM International (2016)
- Phynox cobalt alloy technical data — Aubert & Duval (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.