Adhesive force in relation to the air gap between magnet and steel plate.
This disc magnet is especially suitable for making your own knife racks
45 mm of books in between...
Of course it's totally useless - but if you needed to attach a pile of 50 sheets of A4 paper (80g/m2) to a metal cabinet - you could.
Uster - 21:00- And my magnet is still holding!
The disc magnet S-20-10-N (20x10 mm) can hold approximately 1,75 kg in shear direction, then the steel plate starts sliding down.
If you place a rubber tape between magnet and steel plate, the disc magnet can hold approximately 5,2 kg in shear force; then it starts to slide down.
With a self-adhesive silicone disc between magnet and steel plate (invisible because it has the same diameter as the disc and is only 0,5 mm thin) the disc magnet can hold over 5 kg in shear direction; then it starts to slide down.