Bonded NdFeB

Bonded NdFeB Magnets, Isotropic Plastic Bonded Neodymium Magnets, Custom High Precision Bonding Neodymium Magnets, Polymer-bonded magnetic compounds, Polymer Bonded Rare-earth Magnets

Bonded NdFeB – Bonded Neodymium is made by binding rapid-quenching neodymium (NdFeB) powder with a resin. This is then either compression moulded with epoxy or injection moulded with nylon. The resultant magnets have high dimensional accuracy, are less brittle than normal neodymium magnets but are also less powerful. Being less brittle, they can be more easily made into thin walled ring magnets.

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

 Compression Bonded NdFeB Magnets

Polymer Bonded Magnet By MPCO PDF

 Injection Molded NdFeB Magnets

Compression Bonded NdFeB Magnets


Injection Molded NdFeB Magnets




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.

Bonded NdFeB Magnets

Bonded NdFeB Magnets

Injection Molded Magnets VS Compression Bonded Magnets

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
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.

MPCO provides high precise custom bonded NdFeB magnets according to the specific requirements of customers; PLEASE SEND EMAIL TO US, our professional engineer will work with you.