Countersunk pot magnets assembled with countersunk ring magnets and steel cups, the gap are filled with epoxy glue or plastic ring. The steel cup guide the magnetic lines from one magnetic surface to another one, then the working magnetic surface has much stronger magnetic force,and the back of the pot magnet has very weak magnetism. Different magnetic force demands use specific size or magnetic material. Neodymium countersunk pot magnets have stronger holding force,which are used for heavy loading. Because neodymium pot magnets with countersunk hole are easy to be mounted with screw,they can work as magnetic holder on walls,doors and metal objects.