Friday, August 5, 2011

Magnetism At Its Most Impressive

Rare earth disc magnets have been of considerable technological value since their development approximately four decades ago. They have been utilized in many products  the great and the small and they are commonly purchased and used alone, even for novelty’s sake, because of their sheer magnetic strength. It is the unique combination of components (combined with economy) that have made these magnets so popular.


Neodymium and samarium-cobalt are the two types. Due to the corrosiveness and eventual tendency toward cracking or splitting of both types, they are commonly plated for protection. Neodymium alloy is the later developed, stronger and more affordable of the two, and is composed of neodymium, boron, and iron. The result is supposedly the strongest permanent magnet made, with a magnetic field sometimes in excess of 1.4 teslas, which is almost triple that of alnico or ferrite, so smaller magnets become a space-saving option. Nonetheless, samarium-cobalt retains its place due to its resistance to oxidation and its higher Curie temperature that accommodates equipment of a higher operating temperature.


These rare earth disc magnets have many practical uses. They are vital in computer hard drives as well as headphones and speakers. They are used in fishing reels and bicycles, and even on roller coasters. More recently, they have been made popular as magnetic toys. Regardless of whatever use is applied, there are noteworthy cautions to heed:




Magnets particularly an inch or more in diameter have such strength that they are capable of pinching the skin to the extent of visible injury. There have been documented medical cases of children having swallowed multiple magnets and pinched the digestive tract, necessitating surgery.  They have also been known to cause fracture or breakage of bones. Stronger magnetic fields also have the ability to erase data from credit cards and other such devices.


Despite the potential hazards, neodymium and similar magnets continue to serve great and interesting purposes and receive rave reviews online (particularly the larger ones). It is reported that a three-quarter inch magnet can hold up to 22 pounds of weight. They have been used behind drywall (held by another metal source) to hold items on the visible side of the wall. They can also be epoxy-glued to surfaces to lend an impressive weight-bearing capacity. Varied testimonials online are worth investigating by people who enjoy finding clever ways to manipulate gadgetry.


There is no doubt that rare earth disc magnets have enhanced living in electronic, mechanical and other fields. They are versatile, very affordable and available online in myriad sizes and packs of multiples for convenient shopping. The magnetic neodymium alloy could very well be the toy of the future for children, and a gateway to unfathomable possibilities in the fields of engineering and design.