In the application of magnets, magnetic flux or flux density is an important index to measure their performance (especially in motors), but in some application fields, such as magnetic sorting, fishing, etc., magnetic flux is not an effective measure of separation or adsorption effect, magnetic suction is a more effective index.
Magnetic suction refers to the weight of ferromagnetic material that can be absorbed by the magnet, which is jointly affected by the performance, shape, size and adsorption distance of the magnet. There is no mathematical formula to calculate the suction of a magnet, but we can measure the magnetic suction value through the magnetic suction measuring device (usually measuring the magnetic pull and then converting it into weight), as shown in the figure below. The suction force of a magnet decreases as the distance from the object being adsorbed increases.
1.The ratio of the weight that magnets of different shapes and sizes can lift to their own weight varies greatly, some less than 200 times, some more than 500 times, and some more than 3000 times. Therefore, the 600 times written on the Internet is not completely correct
2.The higher the height of a cylinder or round cake of the same diameter, the greater the weight can be sucked up, and the suction is basically proportional to the height
3.For a cylinder or round cake of the same height (blue cell), the larger the diameter, the greater the weight can be sucked up, and the suction force is basically proportional to the diameter
4.A cylinder or round cake (yellow cell) of the same volume and weight has different diameters and heights, and the weight it can absorb varies greatly. Generally, the longer the orientation direction of the magnet, the greater the suction force
5.Magnets of the same volume do not necessarily have the same suction force, which may vary greatly depending on their shapes; The reverse is also true. Magnets that pick up the same weight of ferromagnetic material may have different shapes, sizes, and weights
Whatever the shape, the length of the orientation is the most important determinant of suction.