If I stack two identical disc magnets on top of each other, does that increase their adhesive force?
Is the adhesive force of several stacked magnets just as high as the adhesive force of an individual magnet of the same size?
The coating and unevenness of magnets reduce the adhesive force of the stack compared to an equally high single magnet.
Uncoated and perfectly stacked magnets are comparable though to an equally high single magnet of the same quality.
The reduction due to coating and unevenness, however, is rather small and the bigger the single magnet, the less it is noticeable.
Therefore, if a magnet is not available in the desired size, combining several magnets could be considered as an alternative.
Please note: The force between the top magnet and the rest of the stack might be much smaller than the force between the stack and the steel plate.
Consequently, when subjected to heavy load, the stack could rip apart somewhere in the middle, even if the theoretical adhesive force was not reached.
This is a disadvantage of a magnet stack compared to a single magnet of the same size.
If I stack two identical disc magnets on top of each other, is their adhesive force then twice as high?
Yes, but only with sufficiently flat disc magnets.
For stacking the following applies: The magnet stack should be half as high as the diameter of an individual disc magnet.
Up to this height, the adhesive force multiplies with each additional magnet.
After that, the adhesive force gain continuously declines.
It strives towards a certain value, which will not be exceeded, no matter how high the stack is.
Example:
| Number of magnets | Adhesive force |
| 1 x S-10-01-N | 0,5 kg |
| 2 x S-10-01-N | 1,0 kg |
| 3 x S-10-01-N | 1,5 kg |
| 4 x S-10-01-N | 1,9 kg |
| 5 x S-10-01-N | 2,1 kg |
| 10 x S-10-01-N | 2,9 kg |
| 50 x S-10-01-N | 3,8 kg |
| 1000 x S-10-01-N | 3,9 kg |