Steel Permendur
Permendur (1J22) is an Fe-Co-V soft-magnetic alloy with the highest saturation flux density of any soft-magnetic material, used when maximum induction must be produced in minimum volume and mass.
Reference datasheet — Permendur 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 MA condition
Permendur tempers and conditions
Permendur is supplied in 4 conditions, soft to hard. MA 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 |
|---|---|---|---|---|---|---|
MADefault Magnetic final anneal | Standard delivered/finished condition for laminations, pole pieces and cores — gives full 2.3 T saturation and low coercivity, but the ordered structure is brittle so no forming afterwards. | 340 | 520 | 3 | 92 HRB | — |
Hot-rolled / forged bar and billet, mill annealed | Bar, billet and ring stock for machined pole pieces, rotor hubs and magnetic-bearing parts; machine first, then final magnetic anneal. | 360 | 560 | 5 | 200 HB | 4.3 % IACS |
Rapid-cooled (disordered) ductile condition, ~750–800 °C water/oil… | Choose when the part must be deep-drawn, bent or heavily machined: quenching suppresses B2 ordering and restores ductility; a final magnetic anneal is still required. | 400 | 620 | 15 | 172 HB | 3.8 % IACS |
Cold rolled | The normal purchase condition for stamping stock: hard, dimensionally stable strip that is blanked/etched first and magnetically annealed afterwards. | 720 | 900 | 2 | 30 HRC | 4.1 % IACS |
Supply forms, finishes and certifications
Ways Permendur is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
WIRE-CD | Cold-drawn wire / rod | Supply form |
What is Permendur?
Permendur (1J22) is an Fe-Co-V soft-magnetic alloy with the highest saturation flux density of any soft-magnetic material, used when maximum induction must be produced in minimum volume and mass. It is specified for weight-critical rotating machines and pole pieces, and is supplied as thin cold-rolled lamination strip, magnetically annealed sheet, hot-rolled annealed bar and cold-drawn wire. Typical values are 340 MPa yield, 520 MPa tensile, 3% elongation and 92 HRB, with service to 500 °C — the highest in this family. Ordered annealed material is brittle (formability score 12, machinability 22), it has no corrosion resistance, and cobalt content makes it expensive; use Fe-Co 50 or 45 Permalloy where cost or permeability drives the choice. Permendur has a density of 8.12 g/cm³ (0.293 lb/in³), heavier than 97% of steel grades. It melts at 1,440°C (2,624 °F). Permendur has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 76% of steel grades. Elongation at break is 3% and the elastic modulus is 207 GPa (30 Msi).
What is Permendur used for?
- aerospace generator/motor laminations
- magnetic pole pieces
- high-flux transformer cores
- electromagnet pole tips
Advantages
- High service temperature — 500°C (932 °F), better than 90% of steel grades
- Good corrosion resistance — 22/100, better than 90% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited ductility — 3%, worse than 99% of steel grades
- High embodied carbon — 7.5 kg CO₂/kg, worse than 99% of steel grades
- Difficult to machine — 22/100, worse than 95% of steel grades
- Limited formability — 12/100, worse than 92% of steel grades
- Poor heat conductor — 29.8 W/m·K (17.2 BTU/hr·ft·°F), worse than 84% of steel grades
Permendur properties
Typical room-temperature values for Permendur-MA; bars are the position among steel grades.
Physical3
Permendur has a density of 8.12 g/cm³ (0.293 lb/in³), heavier than 97% of steel grades. It melts at 1,440°C (2,624 °F).
Mechanical14
Permendur has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 76% of steel grades. Elongation at break is 3% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
Permendur is rated for continuous service to 500°C (932 °F). It conducts heat at 29.8 W/m·K (17.2 BTU/hr·ft·°F), worse than 84% of steel grades. Thermal expansion is 9.6 µm/m·K (5.33 µin/in·°F).
Electrical3
Permendur conducts electricity at 4.3 % IACS, worse than 82% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (22/100), better than 90% of steel grades.
Sustainability4
Producing a kilogram of Permendur takes about 95 MJ of energy and emits 7.5 kg of CO₂ — more than 99% of steel grades. Typical recycled content is 25%.
Manufacturability8
Permendur's machinability is poor (22/100, worse than 95% of steel grades); weldability fair (40/100); formability not recommended (12/100).
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 steel family
Yield strength against density for every steel grade FabDigit runs. Permendur is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Permendur
Is Permendur easy to machine?
Machine in the as-rolled or quenched-disordered state with sharp carbide tooling, rigid setups, low speed and flood coolant — the ordered annealed material chips and cracks; finish-machine before the final magnetic anneal.
Can Permendur be welded?
GTAW, laser and electron-beam welding are feasible with matching or Fe-Co filler and preheat; welds must be re-annealed in dry hydrogen to restore permeability, and weld zones stay locally hard and crack-prone.
Can Permendur be formed, bent or molded?
Blank, stamp, etch or draw in the hard as-rolled or quenched condition; never bend after the ordering anneal, and stress-relieve/final-anneal parts at 840–885 °C in dry H₂ with a slow (≤150 °C/h) cool.
Permendur 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 |
|---|---|---|
| Cogives the 2.3 T saturation | 48.5 – 50 | 49 |
| Vraises resistivity and workability, suppresses ordering embrittlement | 1.4 – 2.2 | 2 |
| Ckept low for low coercivity | ≤ 0.03 | 0.01 |
| Mn | ≤ 0.3 | 0.05 |
| Si | ≤ 0.3 | 0.05 |
| Niresidual | ≤ 0.5 | 0.1 |
| S | ≤ 0.02 | 0.01 |
| P | ≤ 0.02 | 0.01 |
| Febalance, ~49 % | balance |
What surface finishes work on Permendur?
No inherent corrosion resistance — apply electroless nickel, Ni/Sn plating, phosphate or an inorganic C-5-type lamination coating; pole faces polish well but must be protected against humid-air rusting.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel Permendur in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- 2V-Permendur
- Similar grades
- 1J22
How much does Permendur cost?
Permendur is a high-cost steel ($$$$), 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.
Permendur — frequently asked
What is Permendur used for?
Permendur is typically used for aerospace generator/motor laminations, magnetic pole pieces, high-flux transformer cores and electromagnet pole tips. In short: highest saturation soft-magnetic alloy; highest service temperature here; brittle after ordering anneal.
What is the yield strength of Permendur?
Permendur has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 76% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is Permendur easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of steel grades). Machine in the as-rolled or quenched-disordered state with sharp carbide tooling, rigid setups, low speed and flood coolant — the ordered annealed material chips and cracks; finish-machine before the final magnetic anneal.
Can Permendur be welded?
With care — weldability is rated fair (40/100). GTAW, laser and electron-beam welding are feasible with matching or Fe-Co filler and preheat; welds must be re-annealed in dry hydrogen to restore permeability, and weld zones stay locally hard and crack-prone.
What surface finishes work on Permendur?
No inherent corrosion resistance — apply electroless nickel, Ni/Sn plating, phosphate or an inorganic C-5-type lamination coating; pole faces polish well but must be protected against humid-air rusting.
Can Permendur be formed, bent or molded?
Blank, stamp, etch or draw in the hard as-rolled or quenched condition; never bend after the ordering anneal, and stress-relieve/final-anneal parts at 840–885 °C in dry H₂ with a slow (≤150 °C/h) cool.
What is the maximum service temperature of Permendur?
Permendur 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 Permendur-MA and Permendur-CR?
MA is the default condition — standard delivered/finished condition for laminations, pole pieces and cores — gives full 2.3 T saturation and low coercivity, but the ordered structure is brittle so no forming afterwards. CR: the normal purchase condition for stamping stock: hard, dimensionally stable strip that is blanked/etched first and magnetically annealed afterwards. Yield strength is 340 MPa in MA versus 720 MPa in CR.
How much does Permendur cost?
Permendur is a high-cost steel ($$$$), 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
- Hiperco 50 Alloy technical datasheet — Carpenter Technology (2020)
- VACOFLUX 50 soft magnetic cobalt-iron alloy — Vacuumschmelze (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Soft Magnetic Materials) — ASM International (1990)
- ASTM A801 — Standard Specification for Wrought Iron-Cobalt High Magnetic Saturation Alloys — ASTM (2021)
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.