Ferrite is a term for a solid solution that consists almost entirely of iron and a small proportion of carbon. It occurs as a structural component, i.e. as part of the structural composition of steel and cast iron. A key characteristic is its special atomic structure. This gives it certain properties, such as relatively low hardness, increased susceptibility to rust and magnetizability.

In metallography, the atomic structure is referred to as a phase, one of several possible modifications of iron. In the case of ferrite, the iron atoms are arranged in a body-centered cubic lattice. If you imagine a cube, there is an atom at each of the eight corners and a ninth atom in the center of the cube. A small proportion, up to 0.02 percent, of carbon atoms are also contained in ferrite.

Ferrite is ferromagnetic. This means that the magnetic moments - also known colloquially as elementary magnets - are arranged parallel to an externally applied magnetic field. The ferrite therefore becomes magnetic under the influence of a magnetic field. For this reason, components containing ferrite are not suitable for applications with magnetic fields. Magnetic resonance imaging (MRI), for example, is based on detecting fine magnetic resonance signals in a strong external magnetic field in order to calculate a three-dimensional image of the object being examined. It is also essential for the functioning of mine and bomb detection devices that the magnetic fields are not disturbed.

For such applications, ferrite-free components are installed that do not impair the magnetic fields. For this reason, PTM mechatronics also offers its radial piston motor in a ferrite-free variant on. Screws made of non-magnetic materials are used instead of steel. Other components are made of plastic or porcelain, for example.