Why neodymium magnets snap together so forcefully
Neodymium magnets are made from an alloy containing neodymium, iron, and boron. Their material can produce a strong magnetic field in a compact piece. When two magnets are brought near one another with opposite poles facing, each pulls on the other. The force becomes much stronger as the gap shrinks, so a magnet that seems manageable at a distance can suddenly accelerate during the last part of the approach.
That quick closing motion is the hazard. If a finger is between the magnets, their edges can trap and compress it before there is time to pull away. The risk is especially easy to underestimate with small magnets: their size makes them look harmless, even though their attraction can be forceful.
Why separating them can be harder than joining them
Once the faces meet, the magnetic pull holds them together across a very small gap. Pulling straight apart means working directly against that attraction. With larger blocks, the force can be too much for a person to overcome by hand, which is why leverage or equipment may be needed.
A safer approach is to keep fingers out of the path and slide one magnet sideways off the other rather than trying to pull the faces apart. Sliding changes the alignment and lets the magnets separate progressively instead of resisting the full pull all at once. Neodymium magnets are also brittle; if they strike, they can chip or break, sending sharp fragments outward. Their strength is useful precisely because so much force is concentrated in a small space—and that makes handling them with care essential.
