Strontium-Ferrite bar magnet 20mm x 10mm x 3mm

School blackboard magnet .

The color of school magnets is usually black.

They can be used well in education.

It is not dangerous for children, it does not pinch their hands, and at the same time they can be used well in practical education, because they have adequate adhesive strength.

Our ferrite magnets are also suitable for presenting many physical experiments.

Permanent ferrite magnets are made of hard ferrites , which have high coercivity and high remanence after magnetization. Iron oxide and barium or strontium carbonate are used to make hard ferrite magnets. High coercivity means that materials are very resistant to magnetization, which is the basic characteristic of a permanent magnet . They also have high magnetic permeability. These so - called ceramic magnets are cheap and widely used in household products such as fridge magnets . The maximum magnetic field B is about 0.35 tesla, and the magnetic field strength H is about 30–160 kiloampere-turns/meter (400–2000 oersted). The thickness of ferrite magnets is about 5 g/cm3.