NdFeB Block Magnets

What Are Neodymium Block Magnets?

Neodymium block magnets are rectangular-shaped permanent magnets. With their regular flat structure and diverse size options, these block magnets are easy to install and integrate into various magnetic systems. They are widely used in motors, magnetic separation equipment, automation equipment, and industrial holding applications. They are one of the most common magnet shapes used in industrial applications.

NdFeB Block Magnets Specifications

NdFeB block magnets are one of the most commonly customized neodymium magnet specifications. Selecting the right magnet size, grade, and magnetization direction is important for achieving optimal magnetic performance and ensuring reliable assembly.The following parameters can be used as references when customizing neodymium block magnets.

Size Range:

Length: 1mm-200mm
Width: 1mm-100mm
Thickness: 0.5mm-50mm

For special sizes, large-size magnets, or ultra-thin magnets, engineering evaluation is required based on magnetic requirements, manufacturing processes, and application environments.

Magnet Grades:

To ensure stable magnetic performance requirements under different operating temperatures, we provides a complete range of neodymium magnet grades.
Standard Grades: N35-N52;
High Temperature Grades: 30M-50M, 30H-48H, 30SH-44SH, 30UH-40UH, 30EH-38EH, 30AH

In addition, we also provide separate grade series for HRE-free neodymium magnets without heavy rare earth elements.

Magnetization Direction：

Depending on different application requirements, neodymium block magnets can be magnetized in various directions.

Thickness Magnetization:The magnetic poles are distributed on the two opposite thickness surfaces. This is the most common magnetization method for block magnets.

Length Magnetization:The magnetization direction follows the longest dimension of the magnet, and the magnetic poles are located on the two end faces.

Width Magnetization:The magnetization direction follows the width direction of the magnet, and the magnetic poles are located on the two side faces.

Explanation of Halbach Array: Unlike the single magnet described above, which has a uniform magnetization direction, a Halbach array is an assembly technology. By controlling the magnetization direction of each magnet, the magnetic fields between adjacent magnets are enhanced. This creates a stronger and more uniform magnetic field on the working side.

Surface Treatment：

To meet diverse operating environment requirements, TOPMAG offers various surface treatments for NdFeB block magnets, including NiCuNi coating, epoxy coating, zinc coating, gold coating, silver coating, and PTFE coating.
Different coatings can fulfill application needs, such as corrosion resistance, wear resistance, high-temperature performance, or special appearance requirements.

Dimensional Tolerance：

Normally, magnet tolerances are manufactured according to customer requirements.
The following table provides reference tolerances for different precision levels:

Tolerance Grade	Manufacturing Process	Length / Width / Thickness Tolerance	Parallelism / Perpendicularity Tolerance	Typical Applications
Standard Tolerance	Conventional Machining	±0.05 mm – ±0.10 mm	Approximately ±0.05 mm	General assembly applications
Precision Tolerance	Precision Grinding	±0.01 mm – ±0.03 mm	±0.01 mm – ±0.02 mm	High-precision assemblies requiring high dimensional consistency

Applications of Neodymium Block Magnets

Thanks to their high magnetic energy, regular geometric structure, and excellent machinability, neodymium block magnets are widely used in linear motors, magnetic levitation systems, magnetic separation equipment, magnetic holding and lifting devices, sensors, and consumer electronics.

Other Types of Block Magnets

Besides NdFeB block magnets, other magnetic materials can also be used for block-shaped magnets to meet different application requirements.

• Ferrite Block Magnets——Ferrite block magnets offer low cost and excellent corrosion resistance, and are suitable for outdoor environments with low requirements for magnetic strength as well as large-scale application scenarios.

• SmCo Block Magnets——SmCo block magnets provide excellent high-temperature resistance, strong resistance to demagnetization, and outstanding corrosion resistance. They are ideal choices for aerospace applications and high-temperature industrial environments.

• Alnico Block Magnets——Alnico block magnets provide excellent temperature stability. They can maintain stable magnetic performance over a wide temperature range and are widely used in measuring instruments, sensors, and industrial equipment.

Frequently Asked Questions (FAQ)

What are the fixing methods for neodymium block magnets?

ommon fixing methods include epoxy bonding, mechanical fixing, insert molding, and magnetic assembly. The suitable method depends on the application environment and mechanical strength requirements.

How can the demagnetization resistance of NdFeB block magnets be improved?

This can be improved by selecting magnets with higher Hcj values, increasing magnet size, optimizing magnetic circuit design, and using proper assembly methods,ect.

Do neodymium block magnets meet RoHS and REACH requirements?

TOPMAG offers magnet products that comply with international environmental requirements and can provide related material certification documents according to customer needs.

How are NdFeB block magnets packaged and transported?

Since NdFeB magnets have strong magnetic fields, they are usually packaged with magnetic shielding materials, iron boxes, or special shielding packaging to meet transportation safety requirements.

Will the magnetic performance of block magnets decrease over time?

High-quality sintered neodymium magnets have excellent long-term stability. Under normal operating temperatures and environmental conditions, magnetic performance loss is very small. However, high temperatures, strong reverse magnetic fields, or corrosive environments may cause irreversible demagnetization.

Ferrite Magnets