Neodymium magnets must be handled with care to avoid personal injury and damage to the magnets. Fingers and other body parts can get severely pinched between two attracting magnets. Bones can be broken by larger magnets.
Neodymium magnets are brittle. They can peel, crack or shatter if allowed to slam together. Eye protection should be worn when handling these magnets, because shattering magnets can launch pieces at great speeds and sparks may be produced.
The strong magnetic fields of neodymium magnets can also damage magnetic media such as floppy disks, credit cards, magnetic I.D. cards, cassette tapes, video tapes or other such devices. Electronics such televisions, VCRs, computer monitors and other CRT displays can also be damaged.
Children should not be allowed to play with neodymium magnets as they can be dangerous. Small magnets pose a choking 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 device. The strong magnetic fields of the magnets can affect the operation of such devices.
Neodymium magnets are brittle and prone to chipping and cracking. Machining, drilling or other mechanical alterations are not recommended.
Neodymium magnets will begin to lose their magnetic properties if heated above 176° F (82° C).
The Bottom Line: Like any tool or toy, neodymium magnets can be fun and useful, but must always be treated with care.