Neodymium Block Magnet 17.5 x 9 x 2.5 mm N48
 
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. N48 indicates the magnetic grade; NdFeB grades commonly range from N35 to N52, with higher numbers generally indicating stronger magnets. The rectangular block shape is practical for assembly. It is easy to align, provides a good contact surface and fits well into fixtures and grooves.
 
The 17.5×9×2.5 mm block is a good choice where a substantial but manageable hold is needed in workshops or light manufacturing. Even a small gap caused by paint, tape or clearance noticeably reduces magnetic attraction. It performs best on solid steel.
 
Warning: keep away from children. Strong attraction can cause pinching injuries, and the magnets may break. Store them with spacers. Keep them away from bank cards, sensitive electronics and medical devices.