Magnet surface with two magnetic poles ≠ planar 2 pole magnet

In the magnet industry, people often mention magnets with "two poles on a single surface," which are sometimes mistakenly referred to as "planar two-pole magnets." However, these two concepts are not entirely the same. Let's explore the details together.

The so-called two magnetic poles on a surface refers to the presence of two regions of different polarities on a certain surface of a magnet, such as a rectangular magnet magnetized along its length into two poles, with the left half being the N pole and the right half being the S pole. Circular magnets are magnetized radially in the same way, with the left half being N or S and the right half being S or N. In terms of magnetic field distribution, the magnetic lines of these magnets start from one pole region and flow back to the adjacent pole region, resulting in clear magnetic pole boundaries on the surface of the magnet. This distribution can be observed through a Gaussian meter or magnetic pole observation piece.

A planar 2-pole magnet usually refers to a magnet that is magnetized in the thickness direction, but the surface magnetic field is specially processed or designed to present a relative magnetic pole distribution on the upper and lower surfaces. For example, some sensors use planar magnets with single-sided or double-sided 2-pole magnetization.

The accompanying diagram illustrates the pole distribution of a standard planar two-pole circular magnet.

Still don't get it? Here's an example: Take a rectangular neodymium magnet measuring 20×10×2mm. If magnetized along its length, with the left side of the center boundary being the N pole and the right side being the S pole, this is a magnet with “two poles on one face.” However, if we magnetize the same magnet as a planar bipolar magnet, requiring the top and bottom surfaces to exhibit opposing N/S poles, only then can it be called a “planar 2 pole magnet.”

Therefore, having two poles on one surface merely means two polarities appear on the magnet's surface—it does not equate to a planar 2 pole magnet.

Relevant samples;

Planar 4 pole ferrite disc magnet 20mm x 3mm