Neodymium Magnet in Steel Housing with Countersunk Hole 10 x 13 x 5 mm. 
 
Neodymium (NdFeB) is among the strongest magnetic materials and provides substantial holding force for its size. It is much stronger than conventional ferrite magnets and generally has a protective coating because the material can corrode over time. The N indicates the magnetic grade. NdFeB grades commonly range from N35 to N52, with higher numbers generally indicating stronger magnets. The with Hole design for mechanical attachment, allowing screw mounting without adhesive.
 
The 10×13×5 mm size provides a strong hold for practical tasks, including quick assemblies, attachments and technical projects. Holding force depends strongly on the thickness and condition of the metal surface. It is greater on thick steel than on thin sheet metal. Use moderate tightening force, avoid overtightening and use a washer where possible. Impacts or excessive clamping pressure can crack the magnet.
 
Warning: keep out of reach of children. Magnets can snap together suddenly, pinch skin and chip or break on impact. Handle them carefully when bringing them together or separating them. Keep them away from bank cards, sensitive electronics and medical devices.