Pot Magnets

"Pot" magnets, sometimes known as "cup" magnets, are enclosed in a steel "cup", or "pot". This means that the poles are positioned on a single face, with one pole in the form of a ring surrounding the other pole.

This configuration results in the following:

• The back of the magnet has almost no magnetic field associated with it, making the magnet useful where stray fields are not welcome.
• The field is confined largely to the gap between a centre pole and the ring around it. Again, this makes the magnet useful where stray fields are not welcome.
• Unlike standard magnets, the back of a pot magnet can be sunk into a cavity in steel without losing its pull at the surface of the steel.
• The magnet grips very well when placed right against flat steel, but at even a small distance away, it has quite reduced pull. To clarify, they are the worst type of magnet for pulling from a distance.
• It performs better than a similar size standard magnet when pulling to thin sheet steel.
• Their most common application is for cupboard doors, pulling towards a steel washer, bracket, or plate.
• They repel strongly from each other when close, but are quite unsuitable for attracting towards each other.
• The "cup" protects the quite brittle magnet material against fracturing during impact.
• An application for larger ones is for mounting a heavy item against a shipping container, commercial vehicle, heavy machinery, or other solid steel construction.
• For their pull they are often a cheaper option than standard magnets.