Neodymium Ring Magnet 20 x 5.5 x 3 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. Compared with ferrite, neodymium provides much greater magnetic attraction. The magnet generally has a protective surface coating. 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.
 
At Ø20/Ø5.5×3 mm, this magnet provides a strong hold for workshop use, assembly, alignment and technical projects. (Ø20/Ø5.5×3 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 quickly and pinch fingers. They are hard but brittle, so do not allow them to collide. Keep them away from bank cards, sensitive electronics and medical devices.