Neodymium magnet magnetization directions – which one to choose?

Cylindrical magnets: discs and cylinders

Magnets shaped like discs and cylinders can be magnetized axially or diametrically. In the axial variant, the north and south poles are on the flat faces (“top” and “bottom” of the disc), whereas in the diametrical variant they are on the curved sides of the cylinder.

• Axial: Most commonly found in discs, providing the greatest holding force when the flat side is in contact with an opposing flat surface.

• Diametrical: The magnet has its north and south poles around the perimeter; used for example in specialized motors, sensors, or applications requiring torque.

Plate magnets: blocks and rectangular prisms

Plate magnets have three dimensions: length, width, and thickness. The magnetization direction usually corresponds to the thickness, but not always—it depends on the manufacturer's designation. In dimension descriptions, the last number often indicates the magnetization axis.

For example, if a plate magnet measures 20×10×5 mm (length × width × thickness) and the manufacturer notes it is magnetized through 5 mm, this means the poles run through that smallest thickness. In cases where measurements are larger (for instance, 20×10×30 mm), the magnetization axis could be 30 mm if so stated in the specifications.

Ring magnets: cylindrical magnet with a hole

In rings (magnets with a hole), we also distinguish axial (poles on the flat faces) or diametrical (poles on the sides). How the magnet will be used (for instance, mounted on a shaft or lying flat) determines the choice of magnetization direction.

• Axial rings: The north and south poles are on the flat surfaces, often used in applications where the entire face of the magnet makes contact.

• Diametrical rings: The poles are around the perimeter, used for example in motors or rotary sensors.

Magnetic spheres: balls and spheres

Spherical magnets (often called magnetic balls) are typically axially magnetized (between the “top” and “bottom” of the sphere), meaning the north and south poles lie opposite each other along a certain diameter.

Arc magnets (arc shapes)

Arc magnets (known as arc shapes) can be magnetized in several ways: through thickness, around the circumference, or with the north pole on the outer or inner arc surface. The choice often depends on the design of the electric motor or generator where the arc is used.

Summary

Understanding the magnetization direction is crucial for optimal use of a neodymium magnet in any project. Discs, cylinders, blocks, rings, spheres, or arcs—each shape can have a different pole arrangement. Choosing the right variant allows you to achieve maximum holding force in the desired direction and avoid unnecessary efficiency losses. If you are unsure about the proper magnetization direction, consult a specialist or check the manufacturer's documentation.