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  • Segment Arc Motor Magnet

Segment Arc Motor Magnet


Arc motor magnets, also known as segment magnets, are specifically designed for use in electric motors. Our arc shaped neodymium magnets are shaped as curved segments to fit around the rotor, providing an optimal magnetic field configuration. Segment or arc shaped Neodymium magnets are widely used instead of expensive radial rings in electric motors.

Characteristics of Arc Motor Magnets

Shape and Design

Curved Segments: Arc magnets are curved to match the inner circumference of the motor's rotor.

Uniform Magnetic Field: Their shape allows for a more uniform magnetic field, which improves motor efficiency and performance.


Neodymium (NdFeB): The most common material used for arc motor magnets due to its high magnetic strength.

Samarium Cobalt (SmCo): Arc segment magnets are used in applications requiring high temperature stability and corrosion resistance.

Magnetic Properties

High Remanence (Br): Provides strong magnetic fields.

High Coercivity (Hc): Ensures resistance to demagnetization.

Energy Product (BHmax): Indicates the overall energy output of the magnet.

Arc Motor Magnet Applications:

Electric Vehicles (EVs)

Used in brushless DC motors (BLDC) and permanent magnet synchronous motors (PMSM).

Arc magnets provide high torque and efficiency, crucial for performance and range.

Industrial Motors

Found in servo motors, linear motors, and other high-precision motors.

Enhances precision, reliability, and efficiency in automation and manufacturing processes.

Consumer Electronics

Neodymium arc segment magnets are used in high-performance applications such as cooling fans and compact devices.

Ensures efficient operation in limited spaces.

Renewable Energy

Employed in wind turbine generators and other renewable energy systems.

Enhances the conversion efficiency of mechanical energy to electrical energy.

Arc shaped Neodymium Magnets Size:

Normal Size Range: L (Length): 1~180mm, W (Width): 3~180mm, H (Height): 1.5~100mm

Maximum Size: L50 x W180 xH80mm, L180 x W80 xH50mm,

Minimum Size: L1x W3 x H2mm

Orientation Direction Size: Lower than 80mm

Tolerance: Generally +/-0.1mm, Particularly +/-0.05mm

Machining Method:

Generally, the segment requires grinding and EDM cutting from the big block. Sometimes, the approximate final shape achieved after the EDM cutting needs processing with a shaped diamond grinding wheel which provides the precise dimensions and speeds up the machining process. Before coating, the small segment needs vibration tumbling and the big segment needs manual chamfering.

Main Test Items Before Delivery:

To ensure NdFeB magnets meet requirements, we mainly test the following items: size, weight loss, magnetic properties, flux, flux density, angle deviation, magnetic loss, appearance, coating thickness, corrosion resistance, etc. 

Horizon has been focusing on the development and production of high end series of NdFeB rare earth permanent magnets, which are widely used in permanent magnet motors and generators.

Due to their advantage, NdFeB rare earth magnets have become one of the most important components of permanent magnet motors and generators, whose performance and life time mainly depend on the quality of magnets. Generally speaking, the working environment of motors and generators is very harsh. To adapt to this working environment, we have been devoting ourselves to research and developing NdFeB rare earth magnets specially used for permanent magnet motors and generators since its foundation. For this application, the magnets are available in a wide range of shapes such as blockringsegmentloaf, wedge, etc.

Arc motor magnets are a critical component in modern electric motors, providing the necessary magnetic fields for efficient and powerful operation. Their curved design, high magnetic strength, and versatility make them ideal for various applications, from electric vehicles to industrial machinery. Selecting the right arc magnet involves considering factors such as magnetic grade, temperature rating, and environmental conditions to optimize motor performance. Welcome to contact us!

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