25pcs N52 9mm x 9mm x 7.5mm Square Block Rare Earth Neodymium Magnet

Pull Force: 10.10 LB

Dimensions: 9mm x 9mm x 7.5mm thickness, (0.354in x 0.354in x 0.295in) 

Material Features: Neodymium (chemical symbol Nd) is element 60 on the periodic table. It is a rare earth metal and forms one of the Lanthanides series. When added to Iron (Fe) and Boron (B) (chemical formula Nd14Fe21B) the resultant magnets are the strongest magnets currently available. Neodymium magnets are sometimes known as Neo, Neod or NIB magnets. Neodymium magnets are usually coated Nickel-Copper-Nickel plating to prevent the iron from rusting. Neodymium magnets are made of a brittle material. These magnets are not as strong as steel.  They are more like a brittle ceramic.  If you let two magnets slam together, they can crack and break. This is true for magnets large and small.  

Warning: These magnets are very powerful which should be handled with great care. Children should not be allowed to handle neodymium magnets, as they can be dangerous. These magnets are not toys. Small magnets risk a chocking hazard and should never be swallowed or inserted into any part of the body. Never allow neodymium magnets near a person with a pacemaker or similar medical devices. The strong magnetic fields can affect the operation of such devices.