Distance and loss of magnetic strength

When selecting a magnet for your project, be aware that there is a significant difference in the carrying capacity of the magnet when in direct contact compared to when there is a gap made of materials like wood, fabric, glass, or cork.

Magnets are strongest in direct contact

We have listed the strength of all our magnets as the carrying capacity they possess in direct contact with steel or another magnet in a straight pull (i.e., with both components vertical). However, if there is a gap between the magnets or between the magnet and the metal surface, such as with a glass whiteboard or a knife rack with concealed magnets, or if you need to hang several sheets of paper, the magnetic force diminishes with the distance.

Rule of thumb:

- At a distance of 2 mm, the carrying capacity decreases by 70%.

- At a distance of 5 mm, the carrying capacity decreases by 92%.

In other words: at a 2 mm gap, only 30% of the original strength remains, and at a 5 mm distance, just 8% of the strength is left. This is crucial to consider when calculating your strength needs. And beyond 10 cm, the strength is insufficient for anything but electronic magnetism measurement.

We've created a magnet calculator to assess your strength needs for different scenarios. You can find our magnet calculator >> here <<

Therefore, it is most optimal to maintain as little distance as possible between two magnets or a magnet and metal. We're here to guide you to the finish line, even if the gap widens. For example, we've supplied magnets for cleaning 6 cm thick windows. However, you must be aware that large distances require much larger and stronger magnets, which demands more space for the magnet and results in a more costly project. But please contact us – we're eager to advise you on selecting the right magnets.

To give you an idea of size, strength, and price before you start your project, here is a small selection of medium-sized magnets. We stock more than 1000 different sizes, so there are many more beyond these. Further down, we’ll explain a bit about load-bearing capacity in a downward pull.