Wouldn't it be nice to be able heat nuts, bolts, and other mechanical hardware cherry red in seconds without flame! By using an electromagnetic field it is possible by creating small electrical currents in metal parts, that cause the metal part to produce its own internal heat. The magnetic field has no affect on non-metals allowing heat to be applied near plastic objects or other sensitive areas without damage. This rapid heating will cause nuts to heat before the stud gets hot, which creates thermal expansion that allows a frozen nut to be removed with little effort.In the picture on the upper left notice how the nut is hot while the stud is relatively cool. The difference in temperature causes the nut to expand faster than the stud, making it easier to remove. 500F to 600F is usually enough for most applications.
For more information see the "Autotron" which Utilizes induction heating.
See http://www.autotronheater.com/
