What determines the pulling force of a magnet?
The pulling force of a magnet is determined by the Gaussian values and the geometry parameters of the magnet. The higher the Gaussian value, the greater the tensile force for magnets of the same size. The Gaussian rating is determined by the material of the magnet and the grade. For example, for neodymium magnets, the larger the N number, the higher the Gauss rating. So, grade N52 has a higher Gauss rating than N45, as does the pull force for the same size magnet.
Increasing the thickness of a magnet is better than increasing the width. In general, the pulling force is proportional to the thickness of the magnet and the area of the contact surface. Thus, an increase in thickness is better than an increase in width unless the thickness is equal to or greater than the width.
Choosing a round magnet is better than choosing a rectangular magnet. Since a circle has a larger area than a rectangle for the same circumference, you get a stronger magnet than a rectangular one for the same magnet weight.
Finally, select the magnets in the following order,
- Choose a round magnet over a rectangular magnet if a round magnet can be used.
- Increasing the thickness before increasing the contact area, unless the thickness is equal to or greater than the width.