Ring magnets are mainly ordinary axial and radial, multi-pole axial and radial magnetization and other ways, today's topic is through the radial OD magnetization of the ring magnet it is the inner diameter surface whether there is a magnetism problem.
The inner circular surface of a radial OD multipolar magnetized ring will not be magnetic by itself. In a multipole-filled torus, the magnetic field is concentrated in the outer space of the torus and does not directly involve the inner surface. The magnetic field is usually generated by the electric current surrounding the wire, while inside the ring the magnetic field is small or almost zero.
Take a sample for example, the following figure for the radial outer diameter magnetization of the 8-pole ferrite ring magnet, its outer diameter surface magnetic strength of 1800 gauss, while in the inner diameter of the surface is only 130 gauss, weak magnetic.
Magnetization through the diameter magnetized 8-pole ferrite ring outer diameter surface magnetic strength
The magnetic properties of the inner surface of the 8-pole sintered ferrite ring magnetized through the diameter are very, very low.
Through the actual test can be seen, radial diameter magnetization of the multi-pole ring, the inner circular surface is also magnetic, only a very small very small, there is also a spoke to the ring, this can be done inside and outside of the single-pole magnetization method.
Relevant permanent magnet magnetization knowledge;