Ferrite Arc Magnets

Ι What Are Ferrite Arc Magnets?

Ferrite magnets, also called ceramic magnets or hard ferrites, are non-metallic permanent magnets made from Iron Oxide (Fe₂O₃) together with Barium Carbonate (BaCO₃) or Strontium Carbonate (SrCO₃). Produced by a powder metallurgy process, they offer low cost, moderate magnetic performance, and excellent corrosion resistance, making them a popular choice where durability and cost-effectiveness are key requirements.

Ferrite arc magnets are a specialized type of ferrite magnet with a curved shape, mainly used in the rotors and stators of permanent magnet motors. Most are manufactured as segment or tile-style pieces and are often treated as part of the ferrite ring magnet family. Their curved geometry allows them to match the round profile of the motor, directing magnetic force in the required direction. Because of this form, ferrite arc magnets are also commonly known as curved magnets, tile magnets, or segment magnets.

How Ferrite Arc Magnets Are Manufactured?

Ferrite magnets, like many pressed permanent magnets, are difficult to form to precise shapes and dimensions during pressing under an external magnetic field. This makes it hard to produce parts that directly meet the exact requirements of real applications. Therefore, sintered ferrite blanks must be machined afterward so the final magnets match the specified size and tolerance.

Because ferrite is hard, brittle, and electrically insulating, it can only be machined by grinding and slicing to achieve the needed dimensional accuracy, geometric tolerances, and surface finish. For ferrite arc magnets, this is usually done by profile (contour) grinding, since wire-cutting methods are not suitable for ferrite materials.

Magnetization Directions of Ferrite Arc Magnets

Unlike Neodymium arc magnets, which are widely used in both radial flux and axial flux systems, ferrite arc magnets are mainly applied in radial flux motors. They usually have a uniform arc profile or other tailored shapes designed to improve magnetic performance in these machines.

Ferrite arc magnets are typically magnetized diametrically, with the magnetization direction perpendicular to the axis of rotation. They are often arranged in pairs to create the required magnetic flux distribution. In addition, unlike Neodymium arc magnets, ferrite arc magnets can also be produced with true radial magnetization, providing more options for specific motor designs.

Diametrical Magnetization

Ferrite Arc Magnets-Radial Magnetization