Steel 45 Permalloy
45 Permalloy (1J50, NiFe45, 1.3981) is a moderate-nickel Fe-Ni soft-magnetic alloy that offers higher saturation induction than 80-type Permalloy while retaining good permeability.
Reference datasheet — 45 Permalloy 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
45 Permalloy tempers and conditions
45 Permalloy is supplied in 7 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Magnetic (final) anneal | Choose for finished cores/shields: gives maximum permeability and lowest coercivity, but parts become soft and stress-sensitive and cannot be reworked. | 170 | 470 | 45 | 105 HB | 3.8 % IACS |
annealed and cooled in a longitudinal/transverse field (loop shaping) | Pick when a squared (Z-type) or flattened (F-type) B-H loop is needed, e.g. magnetic amplifiers, saturable reactors and pulse cores. | 170 | 470 | 45 | 105 HB | 3.8 % IACS |
ANNDefault Annealed | Standard stocked soft condition: formable and machinable, magnetic properties still to be developed by the customer's final anneal. | 210 | 520 | 40 | 125 HB | 3.8 % IACS |
Hot rolled | Semi-finished heavy sections for further machining; scale must be removed and a full magnetic anneal applied afterwards. | 250 | 540 | 35 | 135 HB | 3.8 % IACS |
Half hard | Compromise temper for parts that need some stiffness/handling strength yet still bend without cracking. | 560 | 720 | 10 | 17 HRC | 3.8 % IACS |
Cold drawn | Use for machined cores, pole pieces and relay armatures where straightness, tolerance and strength are wanted before the final anneal. | 600 | 760 | 15 | 20 HRC | 3.8 % IACS |
Cold rolled | Supplied hard for springy stampings, shims and for customers who stamp then anneal the finished part. | 800 | 950 | 3 | 28 HRC | 3.7 % IACS |
What is 45 Permalloy?
45 Permalloy (1J50, NiFe45, 1.3981) is a moderate-nickel Fe-Ni soft-magnetic alloy that offers higher saturation induction than 80-type Permalloy while retaining good permeability. Engineers choose it where flux density matters more than ultimate permeability; it is supplied mainly as thin cold-rolled strip and stamped laminations in annealed, magnetically annealed, cold-rolled and half-hard conditions. Annealed material runs about 210 MPa yield, 520 MPa tensile and 40% elongation at 125 HB, with service to 400 °C. Magnetic performance only develops after a final hydrogen anneal, so machining, welding and forming must precede it; move to 4-79 Mo-Permalloy or Mu-metal when permeability outweighs saturation. 45 Permalloy has a density of 8.17 g/cm³ (0.295 lb/in³), heavier than 98% of steel grades. It melts at 1,425°C (2,597 °F). 45 Permalloy has a yield strength of 210 MPa (30.5 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 98% of steel grades. Elongation at break is 40% and the elastic modulus is 152 GPa (22 Msi).
What is 45 Permalloy used for?
- small transformer laminations
- relay cores
- current transformer cores
- magnetic amplifiers
Advantages
- Ductile — tolerates forming and impact — 40%, better than 99% of steel grades
- Good corrosion resistance — 32/100, better than 96% of steel grades
- Forms and bends easily — 80/100, better than 93% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Poor heat conductor — 13.5 W/m·K (7.8 BTU/hr·ft·°F), worse than 99% of steel grades
- High embodied carbon — 7.5 kg CO₂/kg, worse than 99% of steel grades
- Low strength — 210 MPa (30.5 ksi), worse than 98% of steel grades
- Low stiffness — 152 GPa (22 Msi), worse than 98% of steel grades
- Low electrical conductivity — 3.8 % IACS, worse than 84% of steel grades
45 Permalloy properties
Typical room-temperature values for 45 Permalloy-ANN; bars are the position among steel grades.
Physical3
45 Permalloy has a density of 8.17 g/cm³ (0.295 lb/in³), heavier than 98% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical14
45 Permalloy has a yield strength of 210 MPa (30.5 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 98% of steel grades. Elongation at break is 40% and the elastic modulus is 152 GPa (22 Msi).
Thermal6
45 Permalloy is rated for continuous service to 400°C (752 °F). It conducts heat at 13.5 W/m·K (7.8 BTU/hr·ft·°F), worse than 99% of steel grades. Thermal expansion is 8.5 µm/m·K (4.72 µin/in·°F).
Electrical3
45 Permalloy conducts electricity at 3.8 % IACS, worse than 84% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), better than 96% of steel grades.
Sustainability4
Producing a kilogram of 45 Permalloy takes about 90 MJ of energy and emits 7.5 kg of CO₂ — more than 98% of steel grades. Typical recycled content is 20%.
Manufacturability7
45 Permalloy's machinability is fair (35/100, worse than 84% of steel grades); weldability good (60/100); formability very good (80/100).
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. 45 Permalloy is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 45 Permalloy
Is 45 Permalloy easy to machine?
Gummy and work-hardening — use sharp positive-rake carbide, heavy feed, low-to-moderate speed and flood coolant; leave a finish anneal after machining to restore magnetics.
Can 45 Permalloy be welded?
TIG, laser and resistance welding are fine with matching Ni-Fe filler and low heat input, but the weld and HAZ lose permeability until the assembly is re-annealed in hydrogen.
Can 45 Permalloy be formed, bent or molded?
Annealed strip stamps, deep-draws and bends readily; avoid residual stress and never straighten a finished core, then hydrogen anneal parts on flat ceramic supports.
45 Permalloy 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 |
|---|---|---|
| Ni45-type; the 1J50 / Alloy 48–50 sub-grades run 47–51 % Ni for higher Bs | 45 – 46.5 | 45.5 |
| Mndeoxidiser/sulphur control | 0.3 – 0.6 | 0.45 |
| Si | 0.15 – 0.3 | 0.2 |
| Ckept low for magnetic softness | ≤ 0.03 | 0.02 |
| S | ≤ 0.02 | 0.01 |
| P | ≤ 0.02 | 0.01 |
| Cu | ≤ 0.2 | 0.05 |
| Febalance, vacuum induction melted | balance |
What surface finishes work on 45 Permalloy?
No anodising; protect with nickel or tin plating, chromate-free lacquer or an epoxy-coated shielding can, and handle annealed shields gently to preserve magnetic performance.
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 45 Permalloy in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- 1J50NiFe451.3981
How much does 45 Permalloy cost?
45 Permalloy 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.
45 Permalloy — frequently asked
What is 45 Permalloy used for?
45 Permalloy is typically used for small transformer laminations, relay cores, current transformer cores and magnetic amplifiers. In short: higher-induction permalloy grade; balances permeability and flux; needs final hydrogen anneal.
What is the yield strength of 45 Permalloy?
45 Permalloy has a typical yield strength of 210 MPa (30.5 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 98% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 45 Permalloy easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of steel grades). Gummy and work-hardening — use sharp positive-rake carbide, heavy feed, low-to-moderate speed and flood coolant; leave a finish anneal after machining to restore magnetics.
Can 45 Permalloy be welded?
Yes — weldability is rated good (60/100). TIG, laser and resistance welding are fine with matching Ni-Fe filler and low heat input, but the weld and HAZ lose permeability until the assembly is re-annealed in hydrogen.
What surface finishes work on 45 Permalloy?
No anodising; protect with nickel or tin plating, chromate-free lacquer or an epoxy-coated shielding can, and handle annealed shields gently to preserve magnetic performance.
Can 45 Permalloy be formed, bent or molded?
Annealed strip stamps, deep-draws and bends readily; avoid residual stress and never straighten a finished core, then hydrogen anneal parts on flat ceramic supports.
What is the maximum service temperature of 45 Permalloy?
45 Permalloy 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 45 Permalloy-ANN and 45 Permalloy-CR?
ANN is the default condition — standard stocked soft condition: formable and machinable, magnetic properties still to be developed by the customer's final anneal. CR: supplied hard for springy stampings, shims and for customers who stamp then anneal the finished part. Yield strength is 210 MPa in ANN versus 800 MPa in CR.
How much does 45 Permalloy cost?
45 Permalloy 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
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Magnetically Soft Materials) — ASM International (1990)
- Soft magnetic Ni-Fe alloy (48–50 % Ni) strip datasheet — VACUUMSCHMELZE / Carpenter-type producer literature (2020)
- ASTM A753 — Standard Specification for Wrought Nickel-Iron Soft Magnetic Alloys (Type 2) — ASTM International (2019)
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.