Pot magnets ferrite
Ferrite pot magnets are countersunk magnets made of a steel pot with a ferrite core. They have a countersunk hole in the middle for screws with countersunk heads. Use them for many purposes. NB! Ferrite magnets are brilliant for outdoor purposes, but the steel pot will get a thin rust layer when used in wet and windy conditions (only changes the magnets look wise - not magnetically).