Pulling force is one of the measuring methods to rate the strength of a magnet. It is typically defined as the force to separate the magnet from a low-carbon steel plate for a direct touch and direct pull condition, where the steel plate should be 20 mm (0.787”) thick. The steel plate surface should be smooth and clean, and the force to pull off the magnet must be perpendicular to the surface.
Based on these factors, the pulling force will be smaller for any of the following situations,
- The magnetic surface is less magnetic than low carbon steel
- The magnetic surface is thinner than 20 mm (0.787”)
- The magnetic surface is rough or not directly touched. For example, the surface is painted or there is debris on the surface
- The pulling force is not perpendicular to the surface
In most applications, the actual pulling force is smaller considering these factors.
Unlike Gauss and Maximum Energy Product, which are more scientific terms, the pulling force is used more often by amateur applications in choosing magnets.