Cobalt-Chrome Alloy Elgiloy
UNS R30003
Elgiloy is a cobalt-chromium-nickel-molybdenum-iron spring alloy (UNS R30003) supplied annealed, half-hard, cold-worked and cold-worked-plus-aged, and strengthened by cold work followed by ageing.
Reference datasheet — Elgiloy 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 CWA condition
Elgiloy tempers and conditions
Elgiloy is supplied in 5 conditions, soft to hard. CWA is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest, most ductile condition — choose for deep drawing, tube forming and further cold reduction. | 480 | 1,000 | 55 | 22 HRC | — |
Cold worked ~30–40 % | Intermediate strength with residual ductility — for parts that still need bending or coiling before final ageing. | 1,250 | 1,500 | 12 | 45 HRC | 1.7 % IACS |
Cold worked | Standard as-supplied wire/strip temper: coil or form the part in this state, then age-harden. | 1,700 | 1,950 | 5 | 52 HRC | — |
CWADefault Cold worked and aged | Final service condition for springs and fatigue-critical parts: maximum elastic limit, best fatigue and relaxation resistance. | 2,000 | 2,200 | 3 | 58 HRC | — |
Heavily cold worked and aged | Ultra-high-strength fine wire for hairsprings, guidewires and micro-springs where maximum tensile is needed. | 2,450 | 2,700 | 1.5 | 62 HRC | — |
What is Elgiloy?
Elgiloy is a cobalt-chromium-nickel-molybdenum-iron spring alloy (UNS R30003) supplied annealed, half-hard, cold-worked and cold-worked-plus-aged, and strengthened by cold work followed by ageing. In the cold-worked and aged condition it reaches about 2000 MPa yield, 2200 MPa tensile, 58 HRC and 210 GPa modulus with high fatigue strength and a corrosion resistance rating of 88, which is why it is used for wire, strip and precision springs in medical and marine service. Limits are 3 % elongation, poor machinability and formability, welding that destroys the cold-work strengthening, and a service ceiling near 400 °C. Phynox is the closest substitute. Elgiloy has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of cobalt-chrome alloy grades. It melts at 1,400°C (2,552 °F). Elgiloy has a yield strength of 2,000 MPa (290 ksi) and a tensile strength of 2,200 MPa (319 ksi) — stronger than 100% of cobalt-chrome alloy grades. Elongation at break is 3% and the elastic modulus is 210 GPa (30.5 Msi).
What is Elgiloy used for?
- pacemaker leads
- surgical springs
- orthodontic wire
- precision springs
Advantages
- High strength — 2,000 MPa (290 ksi), better than 100% of cobalt-chrome alloy grades
- Good corrosion resistance — 88/100, better than 88% of cobalt-chrome alloy grades
Limitations
- Limited service temperature — 400°C (752 °F), worse than 96% of cobalt-chrome alloy grades
Elgiloy properties
Typical room-temperature values for Elgiloy-CWA; bars are the position among cobalt-chrome alloy grades.
Physical3
Elgiloy has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of cobalt-chrome alloy grades. It melts at 1,400°C (2,552 °F).
Mechanical12
Elgiloy has a yield strength of 2,000 MPa (290 ksi) and a tensile strength of 2,200 MPa (319 ksi) — stronger than 100% of cobalt-chrome alloy grades. Elongation at break is 3% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
Elgiloy is rated for continuous service to 400°C (752 °F). It conducts heat at 12.5 W/m·K (7.22 BTU/hr·ft·°F), worse than 77% of cobalt-chrome alloy grades. Thermal expansion is 15 µm/m·K (8.33 µin/in·°F).
Electrical3
Elgiloy conducts electricity at 1.7 % IACS, worse than 92% of cobalt-chrome alloy grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 88% of cobalt-chrome alloy grades.
Sustainability4
Producing a kilogram of Elgiloy takes about 165 MJ of energy and emits 13 kg of CO₂ — more than 57% of cobalt-chrome alloy grades. Typical recycled content is 20%.
Manufacturability8
Elgiloy's machinability is not recommended (12/100, better than 61% of cobalt-chrome alloy grades); weldability poor (25/100); formability not recommended (10/100).
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. Elgiloy is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Elgiloy
Is Elgiloy easy to machine?
Very difficult — work-hardens rapidly; use rigid setups, positive-rake carbide or ceramic tooling, low speed, heavy feed and flood coolant, and machine in the annealed condition where possible.
Can Elgiloy be welded?
Resistance, laser and micro-TIG welding are used on thin sections, but any fusion or brazing heat recrystallises the cold work and locally destroys spring properties; re-age or design joints outside the stressed zone.
Can Elgiloy be formed, bent or molded?
Coil, bend and stamp in the annealed or cold-worked (unaged) condition with generous radii and high tool forces; springback is large, then set the shape by ageing 3–5 h at 510–540 °C.
Elgiloy 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 – 16 | 15 |
| Mo | 6 – 8 | 7 |
| Mn | 1.5 – 2.5 | 2 |
| C | ≤ 0.15 | 0.1 |
| Besmall Be addition distinguishes Elgiloy from Be-free Phynox variants | ≤ 0.1 | 0.05 |
| Febalance, typically ~15–16 % | balance |
What surface finishes work on Elgiloy?
Passivate or electropolish for medical/marine service; takes a bright mirror polish, and PTFE/parylene coatings adhere well — no anodizing.
Equivalent designations
Standards and trade names that resolve to Cobalt-Chrome Alloy Elgiloy in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R30003
- Also called
- F1058 Grade 1
How much does Elgiloy cost?
Elgiloy 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.
Elgiloy — frequently asked
What is Elgiloy used for?
Elgiloy is typically used for pacemaker leads, surgical springs, orthodontic wire and precision springs. In short: highest-fatigue cobalt spring alloy; corrosion-resistant spring wire; age-hardens after cold work.
What is the yield strength of Elgiloy?
Elgiloy has a typical yield strength of 2,000 MPa (290 ksi) and a tensile strength of 2,200 MPa (319 ksi) — stronger than 100% of cobalt-chrome alloy grades. Strength varies by condition: see the 5 listed tempers.
Is Elgiloy easy to machine?
Not especially — machinability is rated not recommended (12/100, better than 61% of cobalt-chrome alloy grades). Very difficult — work-hardens rapidly; use rigid setups, positive-rake carbide or ceramic tooling, low speed, heavy feed and flood coolant, and machine in the annealed condition where possible.
Can Elgiloy be welded?
Not readily — weldability is rated poor (25/100). Resistance, laser and micro-TIG welding are used on thin sections, but any fusion or brazing heat recrystallises the cold work and locally destroys spring properties; re-age or design joints outside the stressed zone.
What surface finishes work on Elgiloy?
Passivate or electropolish for medical/marine service; takes a bright mirror polish, and PTFE/parylene coatings adhere well — no anodizing.
Can Elgiloy be formed, bent or molded?
Coil, bend and stamp in the annealed or cold-worked (unaged) condition with generous radii and high tool forces; springback is large, then set the shape by ageing 3–5 h at 510–540 °C.
What is the maximum service temperature of Elgiloy?
Elgiloy 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 Elgiloy-CWA and Elgiloy-ANN?
CWA is the default condition — final service condition for springs and fatigue-critical parts: maximum elastic limit, best fatigue and relaxation resistance. ANN: softest, most ductile condition — choose for deep drawing, tube forming and further cold reduction. Yield strength is 2,000 MPa in CWA versus 480 MPa in ANN.
How much does Elgiloy cost?
Elgiloy 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 (Grade 1, UNS R30003) — ASTM International (2022)
- Elgiloy Alloy (R30003) technical data — Elgiloy Specialty Metals (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Cobalt alloys) — ASM International (1990)
- GB/T 15005 / YB 3J21 (2018)
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.