What does a neodymium pot magnet consist of?
These super-strong pot magnets are made of the alloy neodymium-iron-boron (NdFeB), which Goudsmit markets under the brand name Neoflux®. The shell or pot ensures magnetic shielding. The bonding surface has a rubber coating for a higher shear force and to prevent scratches.
When does loss of magnetic strength occur?
Neodymium rubber coated pot magnets have an operating temperature of up to 80 °C. When heated to this temperature, the magnet loses 15 to 20% of its magnetic strength. This is not permanent; the force is restored when the magnet returns to the normal ambient temperature.
External magnetic fields may also cause loss of magnetic force. An air gap or non-magnetic materials located between the magnet and workpiece reduce the tensile force.
The specified holding forces are measured under optimum conditions: perpendicular, on a piece of grade 37 steel that has been ground flat with a thickness of 5 mm, without air gap.