Custom neodymium arc magnets for motors, generators, magnetic couplings, and rotor assemblies. Available in different grades, coatings, magnetization directions, and segment dimensions to match your magnetic circuit, working temperature, and assembly requirements.
We support customized NdFeB arc magnets and other shapes based on application requirements, magnetic circuit design, working temperature, coating environment, dimensional tolerance, and assembly structure.
From N35 to N52, including H, SH, UH and other high-temperature grades.
Arc segments, curved blocks, motor magnet segments, chamfered edges, customized inner/outer radius, arc length, thickness, and segment angle.
Custom dimensions with precision machining and tolerance control support.
Ni-Cu-Ni, epoxy, zinc and other coating options for different environments.
Radial magnetization is commonly used for motor arc magnets, with poles on the inner and outer curved surfaces. Parallel, diametrical, and custom pole orientations are also available.
Send your drawing or application requirements for custom NdFeB arc magnet solutions.
We support global industrial buyers with custom sintered NdFeB magnets from sample development to massproduction, combining in-house manufacturing capability, gualified supply resources, and application-orientedtechnical communication.
Our own and qualified partner manufacturing facilities each offer over 3,000 tons of annual sintered NdFeB production capacity, supporting stable lead times, scalable production planning, and long-term supply reliability.
With over ten years of projectand manufacturing experience,we support customers incontrolling key production factors such as machiningtolerance, magneticpertormance consistency,coating reliability and process inspection.
Our magnets are widely used in industrial applications where stable quality,clear communication, and reliable project follow-up are important for both development and mass production projects.
Neodymium arc magnets, also called segment magnets, are designed for rotating magnetic systems where magnets need to fit around a circular rotor, stator, or magnetic assembly. Their curved shape allows better matching with motor structures and helps improve magnetic field distribution in compact, high-efficiency designs.
Compared with rectangular or cylinder magnets, arc magnets are shaped to follow the radius of a rotor or circular assembly. This makes them especially suitable for BLDC motors, PMSM motors, servo motors, generators, magnetic couplings, and other applications where the magnet must work within a curved magnetic circuit.
Depending on the design requirements, neodymium arc magnets can be customized by inner radius, outer radius, arc angle, length, width, thickness, grade, coating, tolerance, and magnetization direction. Common magnetization options include radial, parallel, or customized magnetization patterns based on the magnetic circuit design. ( View NdFeB Magnet Grade Data )
With strong NdFeB magnetic performance and a motor-oriented segment shape, neodymium arc magnets are widely used in rotor assemblies, motor stators, generators, magnetic transmission systems, and custom rotating magnetic devices.
A widely used coating for sintered NdFeB magnets, offering a bright metallic appearance, good dimensional stability, and general corrosion protection for indoor and standard industrial applications.
A cost-effective coating option for general-purpose applications where basic corrosion protection and simple surface appearance are required. Suitable for controlled indoor or mild working environments.
Suitable for applications requiring improved corrosion protection, especially in humid or chemically challenging environments. Epoxy provides good surface coverage and environmental resistance, but should be evaluated according to wear, impact, and assembly conditions.
| Coating Type | Thickness | Appearance | PCT | Salt Spray | Humidity | Acid / Alkali | Oil | Typical Notes |
|---|---|---|---|---|---|---|---|---|
| White Zinc Zn |
≥5 μm | Blue-white | — | ★★ | ★★★ | — | ★ | Basic protection |
| Color Zinc Zn |
≥5 μm | Color-plated red | — | ★★★ | ★★★★ | — | ★ | Improved corrosion resistance |
| Ni-Cu-Ni | ≥15 μm | Silver-white | ★★★ | ★★★★ | ★★★★★ | ★★★ | ★★★ | Common industrial coating |
| Ni-Cu-Ni-Sn | ≥15 μm | Silver-white | ★★★★★ | ★★★★ | ★★★★★ | — | — | Excellent solderability |
| Chemical Ni | ≥5 μm | Silver-white | ★★★★ | ★★★★★ | ★★★★★ | ★★★ | ★★★ | Good overall protection |
| Epoxy | ≥12 μm | Black or grey | ★★★ | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★ | Good corrosion resistance; weaker wear resistance |
| Passivated | ≤2 μm | Black or grey | — | — | ★★★ | — | ★★★ | Thin surface protection |
| Aluminum Al |
≥3 μm | Silver-grey | ★★★★★ | ★★★ | ★★★★ | — | ★★★ | High bonding strength |
| Al + Epoxy | ≥15 μm | Black or grey | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | Excellent corrosion resistance |
| Zn-Al | ≥10 μm | Silver-white or silver-grey | ★★★★★ | ★★★★★ | ★★★★★ | — | ★★★★★ | Strong protection option |
| Everluber | ≥5 μm | Golden yellow | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | High-performance surface protection |
| Teflon | ≥5 μm | Black | ★★ | ★★★ | ★★★★★ | ★★★★★ | ★★★ | Good corrosion resistance |
| Parylene Coating | ≥3 μm | Transparent | ★★ | ★★★ | ★★★★★ | ★★★★★ | ★★★ | Biocompatible coating option |
Note:The star rating reflects the relative corrosion resistance of each coating. Five stars indicate excellent resistance, while “—” means the coating is generally not suitable for that condition. For custom neodymium block magnets, coating selection should be based on humidity, salt spray exposure, chemical contact, assembly method and expected service life.
Custom neodymium arc magnets can be manufactured with different inner radius, outer radius, arc angle, length, width, thickness, chamfers, grooves, and special machining features based on motor drawings or rotor assembly requirements. For BLDC motors, PMSM motors, generators, and magnetic couplings, precise arc magnet dimensions are important for rotor fit, air gap control, magnetic field distribution, and assembly stability. Neomet Tech supports customized arc magnet shapes, tolerances, coatings, and magnetization directions to match your specific magnetic circuit and production needs.
Neodymium arc magnets are widely used in rotating magnetic systems that require strong magnetic force, curved segment geometry, and stable magnetic field distribution. Typical applications include BLDC motors, PMSM motors, servo motors, generators, alternators, magnetic couplings, and rotor assemblies. Their arc shape allows the magnets to fit closely around circular motor structures, helping improve air gap control, torque output, and overall motor efficiency in compact industrial designs.
Neodymium arc magnets can be customized with different magnetization directions according to the motor design and magnetic circuit requirements. Common options include radial magnetization, parallel magnetization, and customized magnetization patterns for rotor or stator assemblies. In addition to magnetization direction, arc magnets can be customized by inner radius, outer radius, arc angle, length, width, thickness, grade, coating, tolerance, and polarity marking to ensure accurate assembly and stable magnetic performance.
Engineering the Extraordinary, Making the Impossible Real
Magnet grade has a direct impact on cost. When the performance grade or coercivity level increases, the material formulation and production process often become more demanding. Higher coercivity grades may require the addition of medium and heavy rare earth elements, as well as more advanced manufacturing processes such as grain boundary diffusion.
As a rough reference, when the performance grade increases by one level, for example from N35 to N38, the material cost may increase by around 5%–15%. When the coercivity level increases, such as from N52M to N52H or from N40SH to N40UH, the cost may increase by approximately 10%–15%.
However, the final price is not determined by grade alone. Coating requirements, magnet size, tolerance, magnetization direction, custom shape, order quantity, and inspection standards can also affect the total cost.
If you are not sure which grade is suitable for your project, please contact us with your application details. Our team can help recommend a suitable NdFeB grade based on working temperature, required magnetic force, coating environment, and cost target.
Get a QuoteIn general sintered NdFeB grade naming, the number indicates the maximum energy product range, while the suffix letter indicates the intrinsic coercivity class. For Chinese standard grades, this classification is defined in GB/T 13560-2017.
For example, in the grade N35H :
“N” indicates that the magnet is made from NdFeB material, also known as neodymium iron boron.
“35” represents the performance grade and refers to the maximum energy product (BHmax). The higher the number, the higher the BHmax value, and the stronger the magnet can be at the same size.
“H” indicates the intrinsic coercivity class. Compared with standard N grade, H-grade materials offer higher Hcj, helping reduce irreversible demagnetization risk under elevated temperature or reverse magnetic field.
You can check detailed NdFeB magnet grade performance data, including Br, Hcj, Hcb, BHmax and maximum operating temperature.
View NdFeB Magnet Grade Data →Sintered NdFeB magnets require a controlled manufacturing process from raw material batching to final inspection. Each step affects magnetic performance, dimensional accuracy, coating reliability, and long-term stability in industrial applications.
Rare earth elements, iron, boron, and alloying elements are prepared according to the required magnet grade and performance target.
The raw materials are melted and cast into alloy flakes to form the base material for sintered NdFeB magnet production.
The alloy is processed into fine powder under controlled conditions to support stable magnetic properties and sintering performance.
The powder is aligned in a magnetic field and pressed into green compacts, forming the basic shape and magnetic orientation.
The pressed compacts are sintered under vacuum to achieve high density, strong magnetic performance, and stable material structure.
Key magnetic properties such as Br, Hcj, Hcb, and BHmax are tested to confirm that the material meets the required grade.
Blocks are cut, ground, or shaped to meet customer drawings, dimensional tolerances, and assembly requirements.
Coatings such as Ni-Cu-Ni, zinc, epoxy, or other protective layers are applied to improve corrosion resistance.
Magnets are magnetized according to the required direction, pole orientation, or custom magnetic circuit design.
Dimensions, coating quality, magnetic direction, surface field, flux, and appearance can be checked based on project requirements.
Magnets are packed with suitable magnetic shielding, separation materials, and export-ready packaging for safe transportation.
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