Magnetic Holding Force: Kilograms or Newtons?

The correct unit for a magnet's pull-off force is the newton (N). The newton is the unit of force in the International System of Units (SI). Magnetic pull-off force is the force needed to separate a magnet from a steel plate or another magnet to which it is attached.

By contrast, the kilogram (kg) is a unit of mass, rather than a unit of force.

The relationship between force and mass involves gravitational acceleration, approximately 9.81 m/s² at the Earth's surface. One newton is the force required to accelerate a mass of one kilogram at 1 m/s².