Ferrite (Ceramic) Magnets

Ferrite magnets are superb in damp, wet or marine environments – Ferrite magnets are corrosion free. Because the iron is already in a stable oxidized form in its structure, the iron cannot oxidize (“rust”) any further when in water. Strontium Ferrite (SrO.6Fe2O3) magnets and Barium Ferrite (BaO.6Fe2O3) magnets are the two types of ceramic Ferrite magnet. The Strontium Ferrite magnets are the most commonly manufactured due to having stronger magnetic properties.

The Ferrite magnets (Ceramic magnets) have a characteristic “pencil lead” colour (i.e. a dark grey colour). They are ferrimagnetic in magnetic performance (good magnetic field and power but, size for size, not as powerful as NdFeB or SmCo). They are extremely popular in motor, generator, loudspeaker and marine designs but are found in almost all industries. e.g. Automotive, Sensor, Machines, Aerospace, Military, Advertising, Electrical/Electronic, Academic, Design House, and R&D. Ferrite magnets can be used at temperatures up to a maximum of +250 degrees C (in a few situations perhaps up to +300 degrees C). There are presently 27 grades of Ferrite Magnet available. The two main grades used today are C5 (also known as Feroba2, Fer2, Y30 and HF26/18) and C8 (also known as Feroba3, Fer3 and Y30H-1). C 5 / Y30 is a general choice of Ferrite Magnet for applications such as overband magnets. C8 / Y30H-1 is a better choice for applications such as loudspeakers and sometimes also motors (C8 has a similar Br to C5 but has a higher Hc and Hci). Ferrite magnets can be produced in many shapes and sizes. Machining to size is limited to grinding processes - the electrically insulating Ferrite material does not allow wire spark erosion. As such, the main shapes are blocks, discs, rings, arcs, and rods.