Probably all of you have heard of neodymium magnets, a certain type of permanent magnets made using rare-earth elements. As a kind of magnetic objects that you can buy, they generate the strongest magnetic field. And because of this outstanding property neodymium magnets are widely used not just to produce toys, but also in different fields of science and technology, including powerful motors, loudspeakers and headphones, actuators and other useful things.
There is another physical property that makes neodymium magnets quite difficult to handle mechanically: they are extremely brittle and may turn to dust even under a slight impact. To prevent this from happening, manufacturers coat these rare-earth magnets in a layer of physically stronger material.
However, neodymium magnets can be very large, making their magnetic field extremely strong. So strong, that it is practically impossible to attach such a magnet to any metal-based object or another magnet.
So how hard it can be to complete such task of joining two ‘beefy’ neodymium magnets? Watch the video below for a very clear explanation and experimental demonstration: