FAQ - Frequently Asked Questions
Are your super magnets really the "world's strongest"?
1. Attractive forceA definition of "power" can be found under FAQ "What do the specifications N40, N42, N45, etc. mean?" :
When we speak colloquially about the "power" of a magnet, we usually mean either the adhesive force on direct contact with a metal plate or the attractive force to a piece of iron (or another magnet) at a certain distance.
2. Resistance to loss of magnetisationThere are permanent magnets that can have just as much attractive force as our neodymium super magnets. Those are referred to as AlNiCo magnets (we have a few of them in our assortment). However, they have one critical disadvantage to our super magnets:
An extremely strong magnetic field, e.g. a large neodymium super magnet, can weaken or annihilate the magnetisation of an AlNiCo magnet and even switch its north and south pole. The super magnet is much more resistant to an "interfering field" than an AlNiCo magnet. Technically speaking, the super magnet has a much higher coercive field.
Magnet strength and the maximum energy product (BH)maxThe attributes "attractive force" and "power of resistance" are usually combined in the physical value "maximum energy product" (BH)max (see physical magnet data).
According to the current state of the art, the grade 52 corresponds to the largest possible maximum energy product of a permanent magnet:
- Maximum achieved today for all permanent magnets: approx. 59 MGOe (sintered NdFeB)
- Estimated technical
- for neodymium magnets: 500 kJ/m3 (63 MGOe)
- for all permanent magnets: approx. 720 kJ/m3 (90 MGOe)
- Estimated theoretical limit for all permanent magnets: 960 kJ/m3 (120 MGOe)
Other important factorsThe power is not only determined by the magnetic material used; equally important are the following factors:
- Volume of the magnet
- Form of the magnet
- Proportions of the magnet (e.g. the ratio of the diameter to the height of a disc magnet)
- Combination with other materials, e.g. is the magnet mounted on a piece of metal, in a metal pot, or is it "free-standing".