Project Description

Plastic Bonded Neo Magnets – Custom Molded, High Precision Neodymium Magnets

Permanent magnets are fragile. Have you ever wonder there is a flexible permanent magnet? Try finding it in the following content.

What is bonded Neodymium Iron Boron (NdFeB) Magnet?

Bonded Neodymium Iron Boron (NdFeB) Magnet, a type of custom molded magnets, is made by binding neodymium (NdFeB) powder with a synthetic resin or polymer.

Injection Molded Magnets VS Compression Bonded Magnets

bonded ndfeb magnet

It can be manufactured in complex forms by means of pressing or extruding.

Bonded ndfeb magnets that are created through injection molding can be formed into complex shapes and also insert molded directly onto other components to produce assembly parts.

Injection bonded magnets can be made from NdFeB, Ferrite or a combination of the two.

Compression bonded neodymium magnets offer higher magnetic property (High energy product up to 12 MGOe) than injection-molded magnets (High energy product up to 6 MGOe), but are limited to more simple geometries.

Compression bonded magnets can be made from either NdFeB or SmCo powders, so it’s also called bonded rare earth magnets.

Bonded Neodymium Magnet Production Process

Injection Molded Magnet: Powder + Binder + Additive – Weighing – Mixing – Extruding Pelletizing – Injection Molding – Finishing – Coating – Magnetization

Compression Molded Magnet: Powder + Epoxy Resin – Weighing – Mixing & Granulation – Particles Adjusting – Compression Molding – Curing – Finishing – Coating – Magnetization

Bond Neo Magnet Grade

Many orders choose grades BNP-8 and BNP-10. You can find more information from our Bond Magnet Grade Page.

Surface Treatment

Although plastic bonded ndfeb magnets have a good corrosion resistance, we still advise to make a coating for them so that the durability is optimal. Epoxy is the most commonly used plating for bonded ndfeb magnet. You can find more information from our Magnet Coating Page.

Magnetization Direction

Due to the isotropy, the plastic bonded magnets can be magnetized in different directions. More complex directions are easy to realize. You can find more information from our Magnetization Direction Page.


There is no necessary for secondary operation in the production process. So the consistency of magnetic performance is good and tolerances are very tight.


  • Relatively Powerful Magnetic force
  • Lower Temperature Resistance
  • Excellent Oxidation Resistance
  • Good Chemical Resistance
  • Extreme resistance to demagnetization
  • Multi-pole magnetization direction
  • Tight Tolerances Possible
  • Good Mechanical Strength


Bonded magnets are mainly used on different motors and sensors, and you can think it is born for auto industry.

It also makes more application possibilities than sintered magnets. For example, the use of higher-density bonded neodymium magnets is helpful in achieving weight and volume reduction in permanent magnet motors, resulting in raw material cost savings.

  • stepper motors
  • actuators
  • magnetic bearings
  • steering control motors
  • magnetic clutch
  • peripheral motors
  • spindle motors
  • auto sensors
  • auto fan motors
  • vacuum cleaner motor
  • air conditioner motor
  • mobile vibration motor

Bonded VS Sintered Neodymium Magnets

The magnetic property of bonded neodymium magnets are weaker compared with sintered neodymium; nevertheless, bonded ndfeb magnets make up many insufficiencies of sintered magnet, such as

  • Precise size
  • Less brittle
  • Light weight
  • A molding assembly
  • More complex shapes
  • More choice of magnetized directions
  • Greater resistance against corrosion

So bonded neodymium magnet is a more flexible alternative to sintered neodymium magnet.

Neodymium Ring Bonded Magnets

Traditionally, to realize multi-pole requirement, the ring magnets used on motors are assembled by segment magnets.

But it is risky while spinning, the adhesive material is out of action. And it’s hard to control the component’s tolerance in the process of assembly. Also it’s not easy to keep magnetic properties’ consistency of all arc magnets.

A better solution is to make multi-poles on a ring magnet instead of segment formed ring.

Now we can provide multi-pole & radial ring sintered ndfeb magnet to meet this requirement. But the limiting factor for production is still a big problem and makes lots of customers seek help from other magnet materials.

Bonded magnet can be magnetized into complex patterns with multiple poles that sintered magnet can’t do. This makes multi-poles ring bonded neodymium magnet an ideal material for different types of motors and sensors.

China Magnets Source Material Limited provides high precise custom bonded NdFeB magnets according to the specific requirements of customers; just hit the button “SEND EMAIL, our professional engineer will work with you.

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