All About Bonded Magnets

Bonded magnets are magnetic materials produced by combining magnetic powders (typically neodymium and ferrite) with binders (such as plastic, rubber, or resin) through a special process, followed by compression molding, injection molding, or other forming techniques. Compared to traditional sintered magnets (such as neodymium-iron-boron magnets and ferrite magnets), bonded magnets offer greater flexibility in shape design and higher dimensional accuracy, making them suitable for applications where magnetic performance requirements are relatively low but shape and precision requirements are high.

Bonded neodymium magnet ring, surface to be protected with epoxy coating

Unique advantages and performance characteristics of adhesive magnets

It can easily produce complex shapes, thin-walled structures, and multi-pole magnetization that cannot be achieved with traditional sintered magnets.

The molding process (especially injection molding and compression molding) ensures extremely high dimensional accuracy (tolerance up to ±0.05 mm) and consistency between batches.

Plastic/rubber adhesives give magnets a certain degree of toughness and impact resistance, reducing the risk of brittle fracture.

Thermoplastic bonded magnets can be injection molded together with other plastic parts to achieve structural and functional integration, simplifying assembly.

Cost advantage of bulk purchasing is obvious.

In terms of performance, magnetic properties and temperature resistance are lower than sintered magnets, limiting their use in some applications that require high magnetic force.

Two main types of bonded magnets

Currently, the two main types of bonded magnets used in the market are bonded ndfeb magnets and bonded ferrite magnets. Bonded ndfeb magnets use neodymium powder as the magnetic material, which is shaped using a binder. They exhibit strong magnetic properties, but due to the use of a binder, their magnetic performance is slightly weaker compared to traditional sintered neodymium-iron-boron magnets. Bonded ferrite magnets use ferrite powder as raw material, with mainstream manufacturing processes including roll-forming (rubber ferrite) and injection molding (injection molded ferrite).

Applications of bonded magnets;

Bonded magnets are widely used in micro motors, home appliances, magnetic sensors, automation equipment, smart homes, door and window seals/advertising displays, and stationery (flexible magnets dominate).

The above is an introduction to adhesive magnets. In recent years, with the growing market for motors and sensors, their application has become increasingly widespread. If you need a quote or would like to inquire about stock samples, please feel free to contact us.

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