What Is Soft Magnetic Alloy? Permalloy Grades, Properties, and Sourcing Basics

Soft magnetic alloy is a material family used where magnetic flux must be generated, guided, or shielded with low energy loss. For engineers and buyers, the practical question is not just what soft magnetic alloy means, but which grade, form, and specification will meet the application requirement.

This article covers the basics: what a soft magnetic alloy is, which Permalloy grades are commonly supplied, what parameters are worth checking, and what a soft magnetic alloy manufacturer should confirm before you commit to a purchase.

Permalloy soft magnetic alloy ingot from Cheng Yuan Alloy.

Why Soft Magnetic Alloy Selection Is Confusing

Soft magnetic alloys are sold under multiple grade systems. A buyer may see 1J79, Ni79Mo4, or 79НМ for one type of high-permeability nickel-iron alloy; 1J50 or FeNi50 for another; and 1J22 or HiperCo50 for a cobalt-iron grade. The grade name helps identify the material family, but it does not tell you whether the strip thickness, annealing condition, and magnetic consistency are right for your transformer core, shielding housing, or motor lamination.

Selection risk is higher for cross-border buyers because local standard names differ and because small differences in composition, heat treatment, or thickness tolerance can change magnetic performance. A clear evaluation process reduces that risk.

Soft Magnetic Alloy Market Background Worth Knowing

The global soft magnetic materials market is estimated at approximately USD 23.0 billion in 2025 and is projected to reach USD 33.9 billion by 2033, according to Grand View Research.

In the more specific soft magnetic alloy material segment, the market is expected to grow at a CAGR of 3.1% from 2024 to 2030 and reach USD 4.14 billion, according to QY Research. Asia Pacific accounts for roughly 41.0% to 49.37% of global soft magnetic material volume in 2025, with China as the leading producer, according to Grand View Research and Mordor Intelligence.

These numbers matter for sourcing decisions because they explain why more buyers are evaluating Chinese soft magnetic alloy manufacturers. The final product choice, however, still depends on material performance rather than market size.

Soft Magnetic Alloy Explained: Permalloy as the Core Example

Permalloy is a soft magnetic alloy made of nickel iron alloy. Model designations include 1J22, 1J79, 1J50, 1J85, and other grades. It is designed for transformer cores and magnetic shielding scenarios, high-frequency electronic equipment, audio transformers, and new energy vehicle components.

One manufacturer in this field is Shijiazhuang Cheng Yuan Alloy Material Co., Ltd, established in 2021 and located in Shijiazhuang, Hebei Province, China. Its main soft magnetic product is Permalloy.

Available Forms for Permalloy Strip, Bar, and Wire

Cheng Yuan Alloy supplies alloy materials in several forms: wire, strip, sheet, bar, wire mesh, powder, tube, stamping, and strand wire. For Permalloy strip, thickness can range from 0.01 mm to 2.0 mm, width from 2 mm to 300 mm, and wire diameter from 0.03 mm to 1.5 mm. Strip width is customizable.

Key Parameters for Soft Magnetic Alloy Strip and Bar

For the Permalloy product range, the published magnetic and physical parameters include the following:

• Initial permeability: 10,000–200,000
• Maximum permeability: 150,000–450,000
• Saturation magnetic flux density (Bs): 0.6–2.35 T
• Coercivity (Hc): 0.4–8.0 A/m
• Saturation magnetostriction coefficient: 0.5–30 ppm
• Core loss at 1 kHz, 0.2 T: 8–35 W/kg
• Resistivity: 40–130 μΩ·cm
• Density: 7.10–8.15 g/cm³
• Curie temperature: 380–950 °C
• Lamination factor: 0.88–0.94
• Surface roughness: Ra ≤ 0.8 μm

These parameters are not just specification values. Initial permeability tells you how easily a shielding housing can absorb and redirect magnetic flux. Saturation flux density tells you how much flux a motor or transformer core can carry. Coercivity and core loss indicate how much energy is lost in alternating-field operation.

Standards Used for Soft Magnetic Alloy Grades

Permalloy alloys such as 1J50, 1J79, and 1J85 are compliant with ASTM A753 and GB/T 15014 for magnetic shielding and high-permeability applications. HiperCo 50, also designated 1J22, contains approximately 49% cobalt and is governed by ASTM A801 Type 1; this grade is commonly used for high-speed rotors and stator laminations.

Vacuum annealing furnace used in the production line for soft magnetic alloys.

Soft Magnetic Alloy Evaluation: Step-by-Step Breakdown

Step 1. Define the Operating Environment

Start with the application. For weak-signal transformers and magnetic shielding, high-permeability nickel-iron grades such as 1J79 and 1J85 are the normal choice. For high-speed motors, aerospace electromagnets, and components that must carry high magnetic flux, 1J22/HiperCo50 is the relevant family. For temperature-compensation components, grades 1J30 to 1J38 are used in automotive and precision instrumentation.

Step 2. Select the Product Form

Choose the form your production line uses: strip, bar, wire, sheet, or another shape. In the Permalloy range, strip thickness starts at 0.01 mm and can go up to 2.0 mm, with width up to 300 mm and custom options.

Step 3. Confirm Magnetic Performance

Compare the required performance with the supplier's documented data. For Permalloy, the typical published range includes initial permeability of 10,000–200,000, maximum permeability of 150,000–450,000, coercivity of 0.4–8.0 A/m, and saturation magnetic flux density of 0.6–2.35 T. Ask how the supplier will confirm those values on your batch.

Step 4. Verify Compliance and Standards

Do not rely on grade names alone. Confirm whether the grade meets the standard your design references. ASTM A753 and GB/T 15014 are relevant for 1J50, 1J79, and 1J85. ASTM A801 Type 1 is the governing specification for HiperCo50/1J22.

Step 5. Check Manufacturer Capability

Verify that the manufacturer can produce and deliver consistently. Shijiazhuang Cheng Yuan Alloy Material Co., Ltd has an R&D team of five engineers, a manufacturing facility covering 200 m², approximately 20 staff, and an annual production output of USD 10–15 million. Export business accounts for 50% of total sales, with major markets in Russia, Germany, France, Italy, the United States, Canada, South Korea, Japan, Brazil, and India.

Use Cases for Soft Magnetic Alloy Grades

1J22 and HiperCo50: Aerospace Generators, High-Speed Motors, and Magnetostrictive Transducers

1J22 is used in the aerospace industry for generators, precision motors, electromagnet poles, and magnetron tubes. It is also suited to precision electromagnet and magnetostrictive transducer projects.

For demanding dynamic applications, 1J22HS offers improved comprehensive magnetic properties and ultra-high mechanical strength. It is designed for aerospace-grade electromagnet pole heads and heavy-load magnetostrictive transducer cores. The material must undergo vacuum hydrogen annealing and dual inspection of mechanical and magnetic performance before delivery.

1J22MS is a variant with optimized magnetic-domain characteristics. It is intended for torque-motor rotors and earphone vibrating diaphragms, where controlled residual magnetism and stable dynamic response under frequent start-stop cycles are required.

Rolling operation for Permalloy strip and bar production.

1J79, 1J85, and 1J50: Magnetic Shielding, Signal Transformers, and Audio Components

1J79, 1J85, 1J50, 1J54, 1J34, and 1J80 are suitable for satellite communication, precision measurement and control, industrial rectifiers, precision gyroscopes, and torque motors. These high-permeability soft magnetic alloys are often used in magnetic shielding components and precision signal transformer cores.

For shielding and transformer applications, the material needs low coercivity, low hysteresis loss, and stable performance over a wide temperature range. Published special requirements for these grades include thickness tolerance within ±0.002 mm and magnetic performance fluctuation below 3% between -60°C and 130°C.

In audio equipment, Permalloy is valued for low-distortion transmission of weak electrical signals. Permalloy audio transformers and coupling transformers are examples of this use.

1J27: Magneto-Mechanical Transducers and Precision Instruments

1J27 is used for speakers, aerospace parts, magnetic bearings, motor rotors, electromagnet poles, relays, and transducers. It provides a high magnetostriction coefficient for magnetic-mechanical energy conversion.

1J30, 1J31, 1J32, 1J33, and 1J38: Magnetic Temperature Compensation

These grades are used in automotive, sensing, and precision instrumentation projects. Their function is to provide stable magnetic compensation under temperature changes, mechanical vibration, and complex electromagnetic environments. Application examples include automotive instruments, aerospace gyroscopes, and industrial wind-speed sensors.

Soft Magnetic Alloy Grade Comparison at a Glance

This comparison is a starting point. The final choice should be based on the actual operating frequency, magnetic field strength, mechanical stress, and dimensional requirements of the project.

Workplace at Shijiazhuang Cheng Yuan Alloy Material Co., Ltd.

Frequently Asked Questions

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Permalloy product packaging from Cheng Yuan Alloy.

If your project needs Permalloy strip, Permalloy bar, wire, or a custom dimension, contact Cheng Yuan Alloy directly.

Conclusion: Soft Magnetic Alloy Selection Starts with Verified Data

Soft magnetic alloy is not a single product. It is a family of nickel-iron and cobalt-iron materials that must be matched to the magnetic, mechanical, and dimensional requirements of the application.

For buyers evaluating 1J22, 1J79, 1J50, 1J85, or similar Permalloy grades, the important step is to compare documented parameters, standards, product forms, and supplier capabilities before placing an order.

Whether you are designing a transformer core, an EMI shielding housing, an audio transformer, or a high-speed motor component, start with the operating environment and verify the manufacturer's material data.