Neodymium Block Magnets
Custom NdFeB block magnets with stable magnetic performance, precision machining, coating options and application-oriented support for industrial magnetic systems.
Neomettech Custom Neodymium Block Magnet Services
We support customized NdFeB block magnets based on application requirements, magnetic circuit design, working temperature, coating environment, dimensional tolerance, and assembly structure.
Grade
From N35 to N52, including H, SH, UH and other high-temperature grades.
Shape
Rectangular, cube, countersunk, stepped and other customized geometries.
Size & Tolerance
Custom dimensions with precision machining and tolerance control support.
Coating
Ni-Cu-Ni, epoxy, zinc and other coating options for different environments.
Magnetization
Through-thickness, lengthwise, or widthwise magnetization and custom polarity arrangements.
Need Custom Block Magnets?
Send your drawing or application requirements for custom NdFeB magnet solutions.
Why Global Buyers Choose Neomet Tech?
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.
Stable Production Capacity
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.
Proven Manufacturing Experience
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.
Long-Term Industrial Cooperation
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.
Why Neodymium Block Magnets?
Neodymium magnets—or more specifically, sintered neodymium magnets are the strongest type of permanent rare earth magnets available today. At the same size, they deliver significantly higher magnetic strength compared to ferrite or AlNiCo magnets, making them ideal for compact and high-performance applications.
The energy product (BH)max of N52 for example can reach up to 414 kJ/m³ (52 MGOe), representing one of the highest magnetic energy densities currently achieved. ( View NdFeB Magnet Grade Data ) Once properly magnetized and used within the specified temperature, corrosion, and magnetic circuit conditions, sintered NdFeB magnets can maintain stable magnetic performance over long service periods.
Made from an alloy of neodymium, iron, and boron, neodymium magnets combine strong intrinsic magnetic properties with mature and stable manufacturing processes. This makes them a reliable material choice for a wide range of industrial applications.
Neodymium block magnets, in particular, are widely used due to their simple geometry and efficient magnetic field distribution. Their shape allows easy integration into assemblies and systems, including motors, magnetic fixtures, and heavy-duty holding or lifting applications.
Key advantages of neodymium block magnets include:
- Simple rectangular geometry for easy assembly integration
- Flat pole surfaces for stable magnetic contact and force transfer
- Custom length, width, and thickness for compact design space
- Thickness, length, or width direction magnetization option
- Suitable for motors, fixtures, sensors, magnetic assemblies, and holding systems
- Coating and temperature grade options for different working environments
Optional Coatings for Neodymium Block Magnets
Sintered NdFeB block magnets require suitable surface protection because the material is vulnerable to corrosion and oxidation. Different coatings provide different levels of corrosion resistance, appearance, adhesion, wear resistance, and assembly compatibility. The right coating should be selected according to the working environment, contact conditions, assembly method, and long-term reliability requirements.
Ni-Cu-Ni Coating
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.
Epoxy Coating
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.
Zinc Coating
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.
| 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 Block Magnet Shapes & Machining Options
Neodymium block magnets can be customized according to installation space, magnetic circuit design, fixing method, and assembly requirements. In addition to standard rectangular blocks, we support machining options such as countersunk holes, stepped structures, thin strips, square plates, cube magnets, and other application-specific block magnet designs. Custom machining helps block magnets fit into real assemblies more accurately, especially for screw-fixed structures, compact magnetic modules, positioning fixtures, sensors, and industrial magnetic assemblies.
Countersunk Block Magnets
Mini Stepped Block Magnets
Countersunk Rectangular Magnets
Cube Neodymium Magnets
Square Plate Magnets
Thin Strip Magnets
Black Coated Cube Magnets
Contact for Customized Shapes
Send your drawing or application requirements for custom NdFeB magnet solutions.
How to Choose the Right NdFeB Magnet Grade?
In 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.
- Required magnetic force or flux output
- Available magnet size and air gap
- Working temperature and reverse magnetic field
- Coating, tolerance, and assembly conditions
- Cost-performance balance for mass production
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 →What Is the Relationship Between Magnet Grades and Cost?
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 QuoteTypical Applications
Neodymium block magnets are widely used in applications where flat surfaces, strong holding force, compact installation, and stable magnetic performance are required. Block magnets are easier to install into rectangular slots, metal housings, plastic parts, magnetic assemblies, and linear magnet arrays.
Typical applications include BLDC motors, PMSM motors, linear motors, magnetic couplings, magnetic separators, holding systems, sensors, magnetic door locks, display fixtures, packaging closures, speaker systems, automation equipment, and custom magnetic assemblies.
In these applications, block magnets support differen tmagnetic functions depending on the design. They can help generate torque in motors, transmit force through an air gapin magnetic couplings, attract ferromagnetic materials inholding systems, provide magnetic signals for positionsensors, or form part of a compact magnetic assembly.
Magnetization Direction and Custom Options
Neodymium block magnets can be magnetized in different directions depending on the application and magnetic circuit design. For rectangular magnets, the most common magnetization direction is through the thickness, where the north and south poles are located on the two largest flat surfaces. This design provides strong holding force and is widely used in magnetic holding systems, packaging closures, display fixtures, magnetic assemblies, and surface-mounted motor magnets.
For special applications, block magnets can also be magnetized through the length or width direction. These options are often used when the magnetic field needs to act from the side surface or end surface of the magnet. Length or width magnetization may be required in sensors, linear magnet arrays, magnetic couplings, automation systems, and custom magnetic assemblies.
In addition to standard magnetization, we can support custom pole orientation, matched pole pairs, alternating N/S arrangements, polarity marking, and magnetic consistency control. For motor, sensor, coupling, and assembly applications, correct magnetization direction is critical to final performance. A magnet with the right size but the wrong magnetic direction may not work properly in the customer’s product.
Manufacturing Process of Sintered NdFeB Magnets
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.
Raw Materials Batching
Rare earth elements, iron, boron, and alloying elements are prepared according to the required magnet grade and performance target.
Alloy Melting
The raw materials are melted and cast into alloy flakes to form the base material for sintered NdFeB magnet production.
Powder Preparation
The alloy is processed into fine powder under controlled conditions to support stable magnetic properties and sintering performance.
Magnetic Field Alignment & Pressing
The powder is aligned in a magnetic field and pressed into green compacts, forming the basic shape and magnetic orientation.
Vacuum Sintering
The pressed compacts are sintered under vacuum to achieve high density, strong magnetic performance, and stable material structure.
Magnetic Property Testing
Key magnetic properties such as Br, Hcj, Hcb, and BHmax are tested to confirm that the material meets the required grade.
Precision Machining
Blocks are cut, ground, or shaped to meet customer drawings, dimensional tolerances, and assembly requirements.
Surface Protection
Coatings such as Ni-Cu-Ni, zinc, epoxy, or other protective layers are applied to improve corrosion resistance.
Magnetization
Magnets are magnetized according to the required direction, pole orientation, or custom magnetic circuit design.
Final Inspection
Dimensions, coating quality, magnetic direction, surface field, flux, and appearance can be checked based on project requirements.
Packaging
Magnets are packed with suitable magnetic shielding, separation materials, and export-ready packaging for safe transportation.
