Neodymium Ring Magnet 18 x 5.5 x 5 mm N48 with Countersunk Hole
 
A neodymium (NdFeB) ring magnet is very strong. It is magnetised in a strong magnetic field during manufacture, providing high magnetic attraction in a compact size. It is much stronger than conventional ferrite magnets and generally has a protective coating because the material can corrode over time. N48 indicates the magnetic grade, commonly ranging from N35 to N52; higher numbers generally indicate greater magnetic attraction. The central hole simplifies mounting and positioning, making it useful for frames, holders and repeatable installations. The chamfered edge is practical: it simplifies installation in a recess and helps protect the edge from damage.
 
This medium size is suitable for stable, strong attachments while remaining manageable to handle. (Ø18/Ø5.5×5 mm) For best results, ensure direct contact with the surface. The magnet provides a particularly strong hold on solid steel.
 
Warning: keep out of reach of children. Swallowing magnets poses a serious risk and requires immediate medical attention. Magnets can snap together suddenly, pinch skin and chip or break on impact. Separate them by sliding them apart. Keep them away from bank cards, sensitive electronics and medical devices.