Neodymium Block Magnet 40 x 12 x 9 mm N35
 
A neodymium magnet (NdFeB) is a very strong magnet 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. N35 indicates the magnetic grade; NdFeB commonly ranges from N35 to N52, with a higher number generally indicating a stronger magnet. The rectangular shape is useful for frames, edges and applications requiring an elongated, stable magnet.
 
This size provides substantial magnetic attraction and is suitable for strong attachments and robust projects. Even a small gap caused by paint, tape or clearance noticeably reduces attraction. It performs best on solid steel.
 
Warning: not suitable for children. Two magnets can snap together quickly, pinch fingers and crack or chip. Separate them carefully and avoid impacts. Keep them away from medical devices and objects sensitive to magnetic fields, including cards and electronics.