Neodymium Block Magnet 20 x 20 x 3 mm N52
 
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. Its magnetic attraction is greater than that of ferrite magnets, and the surface coating helps reduce corrosion. N52 indicates the magnetic grade; NdFeB grades commonly range from N35 to N52, with higher numbers generally indicating stronger magnets. The block shape is easy to position, provides a large contact area on flat surfaces and fits readily into a variety of holders.
 
The 20×20×3 mm block is a good choice where a substantial but manageable hold is needed in workshops or light manufacturing. For good results, use a flat, clean metal surface. Any gap caused by thick paint or an uneven surface reduces holding force.
 
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.