What should I know about gauss?

Gauss is a term often heard in connection with the strength of a magnet. It's not wrong either, but often people talk past each other since gauss can be different values for the same magnet because gauss can be measured in different ways. We will come to this. For now, it's sufficient to know that gauss tells you something about the magnetism of a magnet.
Gauss is a unit that tells you the amount of magnetism in an area. In other words, the magnetic density. More precisely, 1 gauss is equal to 1 line of flux in 1 cubic centimetre. The weakest magnet we can imagine will therefore have 1 flux line running from the magnet's North Pole to South Pole. A more realistic example is a magnet with a gauss of 11700, which therefore has 11700 gauss lines from the magnet's North Pole to South Pole.

In most everyday situations, Gauss is not relevant to deal with. Most people just want to know how many kilos a magnet can hold, and Gauss doesn't say anything about that. Gauss, on the other hand, is often used in electronics, electric motors and other advanced fields. Since most of our magnets are made of the material neodymium, we will look at how gauss is used in this context. Therefore, we will look at two commonly used measurement methods that use gauss as a unit of measurement.

Brmax or just Br describes the magnetic induction that remains in a magnet after the magnetising field has been removed. Brmax is measured in gauss, and for neodymium magnets it is written as a value from N35 to N55. It is a material value that is independent of the shape of the magnet, so there is a 1:1 relationship between an N number and gauss. For example, N35 corresponds to 11700-12100 gauss. On the product pages you can see both the N-number and the gauss number.

While Brmax was a material value measured in gauss, gauss is also used to indicate how strong the magnetic field is at the magnet's surface. The strength of the surface field depends on several things such as the material, the shape of the magnet and how the magnet is used. The strength of the surface field is therefore different depending on the size or shape of the magnet. Furthermore, the surface field can be defined in several ways. It can be calculated using mathematical formulae or it can be measured with a Gaussmeter. If the surface field is measured, it is done directly on the surface of the magnet, but it can be different where on the surface it is measured. These things mean that a magnet's surface field can be different for the same magnet at different magnet retailers because there is no standardised way of measuring it.

• The Brmax and N-number is a material value that can be looked up in a table. Therefore, the value is always the same regardless of which magnet retailer you buy from.
• The Brmax and N-number do not tell you how many kilos a magnet can lift. A large magnet with a low Brmax and N-number can therefore be much stronger (lift more kilos) than a smaller magnet with a high Brmax and N-number.
• If two magnets have the same shape and size, the magnet with the higher Brmax and N-number will be stronger.
• The surface field is a better indication than the Brmax and N-number when determining the strength of a magnetic field. This is because it is measured at the surface of the magnet. But it doesn't tell you anything about how many kilos a magnet can lift.
• A magnet's surface field can be difficult to compare across multiple magnet retailers because it can be measured in multiple ways.
• Not all magnet retailers indicate the surface field. For example, we do not currently do so either.
• Be aware that some retailers market their magnets as powerful because they have a high gas value. I hope the above helps to explain why gauss is not relevant in many cases.