A stud pot magnet has a stud (cylinder of stainless steel) protruding from the top of its steel shell.
Stud pot magnets can be used as antenna mounts on car roofs, or to hang promotional signs from the ceiling of supermarkets, or to be the light fitting for a magnetic down light.
There are three types of stud pot magnet: internal threaded studs, external threaded studs, and plain studs.
Internal threaded studs
An internal threaded stud is a plain stud with an internal threaded centre. The added thread length inside the stud allows a more secure hold with a threaded bolt than without the stud, as on an internal threaded pot magnet.
The internal threaded hole allows the pot magnet to be attached to non-ferromagnetic materials which have corresponding grooves such as threaded bars, bolts, or hooks. The internal threaded hole can fit M4 to M20 threaded hooks and bolts.
Internal threaded stud pot magnets can come with a hook attachment. When a hook is attached to an internal threaded stud pot magnet, the two are known as a ceiling magnet. This is often used to hang promotional signs to supermarket ceilings.
Internal threaded stud pot magnets are also known as female threaded pot magnets. They can attach themselves to external threaded stud pot magnets, which are also known as male threaded pot magnets. This is particularly useful for storage as it allows the two pot magnets to be stored together without one demagnetising the other (see Magnets glossary).
External threaded studs
External threaded studs have continuous grooves, known as threads, in a spiral pattern around the outside. They can either be screwed into a threaded hole or placed through a plain hole and then held in place with a nut.
A plain stud is a stud without any threads or markings. As it has no threads, the plain stud is riveted to non-ferromagnetic materials.
“Riveting” is achieved by punching the stud into the material with a rivet gun. This causes the top of the stud to bend into an umbrella shape, holding the stud pot magnet in place.