Why the grade is the whole story
Neodymium magnets are graded N35 to N52. The number is the maximum energy product, which in practice is how hard the disc pulls for its size. N52 is the strongest commercially available grade, and on a towel that difference is not academic: a weak magnet lets go the first time the trolley hits a ridge, and you finish the round with a muddy towel.
Pull force of 48kg sounds enormous for a piece of fabric, and that is the point. The towel is never carrying 48kg. It is carrying its own weight plus whatever water it has absorbed, through repeated vibration, on a surface that is often wet. Overspecify the disc and it simply never fails.








