Steel Fe-Co 50 (unalloyed)-A (Solution annealed)
Temper
Pick after all stamping/machining is done: gives full soft-magnetic performance (Bs ≈ 2.35 T, low Hc) but the ordered B2 structure leaves the part very brittle.
Values for the A condition
Other Fe-Co 50 (unalloyed) tempers and conditions
Fe-Co 50 (unalloyed) is listed in 4 conditions; see the grade overview at Fe-Co 50 (unalloyed).
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AThis page Solution annealed | Pick after all stamping/machining is done: gives full soft-magnetic performance (Bs ≈ 2.35 T, low Hc) but the ordered B2 structure leaves the part very brittle. | 350 | 520 | 2 | 93 HRB | 27 % IACS |
Hot rolled | Bar and thick-section supply for machined pole pieces and cores, delivered soft enough to turn/grind before the customer's final magnetic anneal. | 380 | 560 | 4 | 14 HRC | 25 % IACS |
Rapid cooled / quenched from ~750–800 °C | Choose when some ductility is needed for bending, shearing or light forming — fast cooling suppresses B2 ordering, at the cost of lower permeability until re-annealed. | 400 | 620 | 8 | 20 HRC | 19 % IACS |
CRDefault Cold rolled | Standard supply condition for thin lamination strip: hard, work-hardened and disordered enough to stamp, magnetic properties developed later by the user's final anneal. | 800 | 900 | 1.5 | 32 HRC | 23 % IACS |
What is Fe-Co 50 (unalloyed)-A?
Fe-Co 50 (unalloyed)-A is Fe-Co 50 (unalloyed) in the A temper — pick after all stamping/machining is done: gives full soft-magnetic performance (Bs ≈ 2.35 T, low Hc) but the ordered B2 structure leaves the part very brittle. Fe-Co 50 (unalloyed)-A has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 74% of steel grades. Elongation at break is 2% and the elastic modulus is 210 GPa (30.5 Msi). Fe-Co 50 (unalloyed)-A has a density of 8.2 g/cm³ (0.296 lb/in³), heavier than 98% of steel grades. It melts at 1,470°C (2,678 °F). CR is the default condition FabDigit quotes; A is available on request or by drawing note.
Advantages
- High electrical conductivity — 27 % IACS, better than 100% of steel grades
- High service temperature — 500°C (932 °F), better than 90% of steel grades
Limitations
- Limited ductility — 2%, worse than 99% of steel grades
- Limited formability — 5/100, worse than 99% of steel grades
- High embodied carbon — 8.5 kg CO₂/kg, worse than 99% of steel grades
- Low fracture toughness — 30 MPa·√m (27.3 ksi·√in), worse than 96% of steel grades
- Difficult to machine — 30/100, worse than 89% of steel grades
Fe-Co 50 (unalloyed)-A properties
Typical room-temperature values for Fe-Co 50 (unalloyed)-A; 13 are specific to this condition. Other listed values are Fe-Co 50 (unalloyed) reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
Fe-Co 50 (unalloyed)-A has a density of 8.2 g/cm³ (0.296 lb/in³), heavier than 98% of steel grades. It melts at 1,470°C (2,678 °F).
Mechanical16
Fe-Co 50 (unalloyed)-A has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 74% of steel grades. Elongation at break is 2% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
Fe-Co 50 (unalloyed)-A is rated for continuous service to 500°C (932 °F). It conducts heat at 43 W/m·K (24.8 BTU/hr·ft·°F), better than 51% of steel grades. Thermal expansion is 9.5 µm/m·K (5.28 µin/in·°F).
Electrical3
Fe-Co 50 (unalloyed)-A conducts electricity at 27 % IACS, better than 100% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of Fe-Co 50 (unalloyed)-A takes about 110 MJ of energy and emits 8.5 kg of CO₂ — more than 99% of steel grades. Typical recycled content is 25%.
Manufacturability8
Fe-Co 50 (unalloyed)-A's machinability is poor (30/100, worse than 89% of steel grades); weldability poor (20/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Fe-Co 50 (unalloyed)-A
Is Fe-Co 50 (unalloyed) easy to machine?
Machine in the quenched/disordered or hot-rolled annealed state with sharp carbide tooling, rigid setups, low speed and flood coolant — ordered material chips and cracks; grinding is preferred for finished pole faces.
Can Fe-Co 50 (unalloyed) be welded?
Poor: resistance/laser tack or EB welding only, with post-weld high-temperature anneal; the fusion zone and HAZ order on cooling and crack readily, and any weld degrades local permeability.
Can Fe-Co 50 (unalloyed) be formed, bent or molded?
Blank and stamp thin strip in the cold-rolled hard or rapidly cooled condition with tight die clearance; avoid bending fully annealed material, and re-anneal in dry hydrogen after all forming.
What surface finishes work on Fe-Co 50 (unalloyed)?
No anodizing — protect with phosphating, oxide/varnish lamination coating, electroless nickel or thin electroplate; keep interlaminar coatings thin because low resistivity already increases eddy-current loss.
Fe-Co 50 (unalloyed) 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 |
|---|---|---|
| Conominal 50 % Co binary | 48.5 – 50.5 | 49.5 |
| C | ≤ 0.03 | 0.01 |
| Mn | ≤ 0.3 | 0.1 |
| Si | ≤ 0.3 | 0.1 |
| Niresidual | ≤ 0.3 | — |
| Vdeliberately not added — distinguishes this grade from 1J22/Permendur V | ≤ 0.1 | 0 |
| S | ≤ 0.02 | — |
| P | ≤ 0.02 | — |
| Fe | balance | — |
Fe-Co 50 (unalloyed)-A — frequently asked
What is Fe-Co 50 (unalloyed)-A used for?
Fe-Co 50 (unalloyed)-A is typically used for magnetic pole pieces, high-flux solenoid cores and specialty relay armatures. In short: vanadium-free Fe-Co alloy; high saturation, low ductility; grinding preferred over machining.
What is the yield strength of Fe-Co 50 (unalloyed)-A?
Fe-Co 50 (unalloyed)-A has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 74% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is Fe-Co 50 (unalloyed)-A easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine in the quenched/disordered or hot-rolled annealed state with sharp carbide tooling, rigid setups, low speed and flood coolant — ordered material chips and cracks; grinding is preferred for finished pole faces.
Can Fe-Co 50 (unalloyed)-A be welded?
Not readily — weldability is rated poor (20/100). Poor: resistance/laser tack or EB welding only, with post-weld high-temperature anneal; the fusion zone and HAZ order on cooling and crack readily, and any weld degrades local permeability.
What surface finishes work on Fe-Co 50 (unalloyed)-A?
No anodizing — protect with phosphating, oxide/varnish lamination coating, electroless nickel or thin electroplate; keep interlaminar coatings thin because low resistivity already increases eddy-current loss.
Can Fe-Co 50 (unalloyed)-A be formed, bent or molded?
Blank and stamp thin strip in the cold-rolled hard or rapidly cooled condition with tight die clearance; avoid bending fully annealed material, and re-anneal in dry hydrogen after all forming.
What is the maximum service temperature of Fe-Co 50 (unalloyed)-A?
Fe-Co 50 (unalloyed)-A is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Fe-Co 50 (unalloyed)-CR and Fe-Co 50 (unalloyed)-A?
CR is the default condition — standard supply condition for thin lamination strip: hard, work-hardened and disordered enough to stamp, magnetic properties developed later by the user's final anneal. A: pick after all stamping/machining is done: gives full soft-magnetic performance (Bs ≈ 2.35 T, low Hc) but the ordered B2 structure leaves the part very brittle. Yield strength is 800 MPa in CR versus 350 MPa in A.
Sources
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Soft Magnetic Alloys) — ASM International (1990)
- Fe-Co 50 / Permendur strip technical data — Vacuumschmelze / Carpenter Technology (comparative Fe-Co data) (2022)
- Soft magnetic Fe-Co alloy property compilations (Bozorth, Ferromagnetism) — IEEE Press reissue (1993)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.