Cobalt-Chrome Alloy F1537 Alloy 1
ASTM F1537 Alloy 1 · UNS R31537 · ISO 5832-12 Alloy 1
ASTM F1537 Alloy 1 (UNS R31537) is the low-carbon wrought Co-Cr-Mo implant alloy, available annealed, hot worked or warm worked in bar, rod and wire forms.
Reference datasheet — F1537 Alloy 1 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 ANN condition
F1537 Alloy 1 tempers and conditions
F1537 Alloy 1 is supplied in 3 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Most commonly stocked raw bar condition: maximum ductility for subsequent forging, machining or forming of implant components. | 610 | 1,000 | 35 | 29 HRC | — |
Hot Worked | Choose for near-net-shape forgings (stems, knee components) needing higher strength than annealed with still-good ductility. | 850 | 1,200 | 22 | 35 HRC | — |
Warm Worked | Highest-strength condition of Alloy 1 — pick for slender, highly loaded implants (femoral stems, spinal rods) where fatigue strength governs. | 1,050 | 1,400 | 18 | 42 HRC | — |
What is F1537 Alloy 1?
ASTM F1537 Alloy 1 (UNS R31537) is the low-carbon wrought Co-Cr-Mo implant alloy, available annealed, hot worked or warm worked in bar, rod and wire forms. The lower carbon gives the best ductility and fatigue life in the F1537 family — 610 MPa yield, 1000 MPa tensile, 35 % elongation, 285 HB (29 HRC), 230 GPa modulus and corrosion resistance rated 92/100 — along with the highest weldability score in the group at 55/100. Strength is well below Alloy 2 and Alloy 3, and machinability is still poor at 14/100. Use Alloy 2 where higher yield strength is required. F1537 Alloy 1 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of cobalt-chrome alloy grades. It melts at 1,330°C (2,426 °F). F1537 Alloy 1 has a yield strength of 610 MPa (88.5 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 58% of cobalt-chrome alloy grades. Elongation at break is 35% and the elastic modulus is 230 GPa (33.4 Msi).
What is F1537 Alloy 1 used for?
- Hip and knee implant components
- Trauma fixation devices
- Bone plates and screws
- Spinal rods and connectors
- Modular implant connectors
- Dental frameworks
- Reusable surgical instruments
Advantages
- Good corrosion resistance — 92/100, better than 100% of cobalt-chrome alloy grades
- Tough — resists crack growth — 100 MPa·√m (91 ksi·√in), better than 97% of cobalt-chrome alloy grades
- Polishes to a fine finish — 92/100, better than 93% of cobalt-chrome alloy grades
- Forms and bends easily — 35/100, better than 86% of cobalt-chrome alloy grades
- Ductile — tolerates forming and impact — 35%, better than 85% of cobalt-chrome alloy grades
F1537 Alloy 1 properties
Typical room-temperature values for F1537 Alloy 1-ANN; bars are the position among cobalt-chrome alloy grades.
Physical3
F1537 Alloy 1 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of cobalt-chrome alloy grades. It melts at 1,330°C (2,426 °F).
Mechanical16
F1537 Alloy 1 has a yield strength of 610 MPa (88.5 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 58% of cobalt-chrome alloy grades. Elongation at break is 35% and the elastic modulus is 230 GPa (33.4 Msi).
Thermal6
F1537 Alloy 1 is rated for continuous service to 600°C (1,112 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 55% of cobalt-chrome alloy grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
F1537 Alloy 1 conducts electricity at 1.9 % IACS, worse than 52% of cobalt-chrome alloy grades.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 100% of cobalt-chrome alloy grades.
Sustainability4
Producing a kilogram of F1537 Alloy 1 takes about 210 MJ of energy and emits 14 kg of CO₂ — more than 80% of cobalt-chrome alloy grades. Typical recycled content is 20%.
Manufacturability8
F1537 Alloy 1's machinability is not recommended (14/100, better than 71% of cobalt-chrome alloy grades); weldability good (55/100); formability fair (35/100).
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. F1537 Alloy 1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with F1537 Alloy 1
Is F1537 Alloy 1 easy to machine?
Very difficult: rigid setups, sharp positive-rake carbide or ceramic tools, low speed / heavy feed and flood coolant to avoid work-hardened glaze; grinding and EDM are common for finish features.
Can F1537 Alloy 1 be welded?
Low carbon content makes it the most weldable F1537 alloy — GTAW or laser/electron-beam with matching filler, clean argon shielding, low heat input; post-weld solution anneal restores ductility.
Can F1537 Alloy 1 be formed, bent or molded?
Cold formability is poor due to the very high work-hardening rate; forge or upset hot (≈1050–1180 °C) or warm work below recrystallisation to raise strength, with intermediate anneals.
F1537 Alloy 1 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 |
|---|---|---|
| Cr | 26 – 30 | 28 |
| Mo | 5 – 7 | 6 |
| Ni | ≤ 1 | 0.3 |
| Fe | ≤ 0.75 | 0.3 |
| CAlloy 1 = low carbon | ≤ 0.14 | 0.05 |
| Si | ≤ 1 | 0.5 |
| Mn | ≤ 1 | 0.5 |
| N | ≤ 0.25 | 0.15 |
| Cobalance, nominally ~62–64 % | balance | — |
What surface finishes work on F1537 Alloy 1?
Not anodizable; electropolish, passivate per ASTM F86, and mirror-polish bearing surfaces (Ra < 0.05 µm); porous or HA coatings can be applied for bone ingrowth.
Equivalent designations
Standards and trade names that resolve to Cobalt-Chrome Alloy F1537 Alloy 1 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R31537
- ISO
- 5832-12 Alloy 1
How much does F1537 Alloy 1 cost?
F1537 Alloy 1 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.
F1537 Alloy 1 — frequently asked
What is F1537 Alloy 1 used for?
F1537 Alloy 1 is typically used for hip and knee implant components, trauma fixation devices, bone plates and screws, spinal rods and connectors, modular implant connectors and dental frameworks. In short: most weldable F1537 alloy; highest ductility Co-Cr-Mo; low-carbon implant grade.
What is the yield strength of F1537 Alloy 1?
F1537 Alloy 1 has a typical yield strength of 610 MPa (88.5 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 58% of cobalt-chrome alloy grades. Strength varies by condition: see the 3 listed tempers.
Is F1537 Alloy 1 easy to machine?
Not especially — machinability is rated not recommended (14/100, better than 71% of cobalt-chrome alloy grades). Very difficult: rigid setups, sharp positive-rake carbide or ceramic tools, low speed / heavy feed and flood coolant to avoid work-hardened glaze; grinding and EDM are common for finish features.
Can F1537 Alloy 1 be welded?
Yes — weldability is rated good (55/100). Low carbon content makes it the most weldable F1537 alloy — GTAW or laser/electron-beam with matching filler, clean argon shielding, low heat input; post-weld solution anneal restores ductility.
What surface finishes work on F1537 Alloy 1?
Not anodizable; electropolish, passivate per ASTM F86, and mirror-polish bearing surfaces (Ra < 0.05 µm); porous or HA coatings can be applied for bone ingrowth.
Can F1537 Alloy 1 be formed, bent or molded?
Cold formability is poor due to the very high work-hardening rate; forge or upset hot (≈1050–1180 °C) or warm work below recrystallisation to raise strength, with intermediate anneals.
What is the maximum service temperature of F1537 Alloy 1?
F1537 Alloy 1 is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between F1537 Alloy 1-ANN and F1537 Alloy 1-WW?
ANN is the default condition — most commonly stocked raw bar condition: maximum ductility for subsequent forging, machining or forming of implant components. WW: highest-strength condition of Alloy 1 — pick for slender, highly loaded implants (femoral stems, spinal rods) where fatigue strength governs. Yield strength is 610 MPa in ANN versus 1,050 MPa in WW.
How much does F1537 Alloy 1 cost?
F1537 Alloy 1 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 F1537 — Standard Specification for Wrought Cobalt-28Chromium-6Molybdenum Alloys for Surgical Implants (UNS R31537, R31538, R31539) — ASTM International (2020)
- ISO 5832-12 — Implants for surgery, metallic materials, Part 12: Wrought cobalt-chromium-molybdenum alloy — ISO (2019)
- ASM Handbook Vol.23 — Materials for Medical Devices — ASM International (2012)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- Medical-grade Co-28Cr-6Mo bar datasheets (Carpenter, Sandvik, VDM) — various producers (2023)
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.