Given:
magnet grade N35, Hc = 954930 A/m, Br = 1.26 T;
relative magnetic permeability of the plate μsteel = 1000.
Task:
Calculate the pulling force of the magnet attraction to the steel plate.
Solution:
To calculate the pulling force accurately, and avoid integration along the edge dividing media with large difference in magnetic permeabilities, we place the magnet at a small distance δ = 0.005" (0.127 mm) from the steel plate. Integration contour is drawn in the air around the magnet.
Result: Magnetic field of the brick permanent magnet in vicinity of the steel wall.