How hot can I heat a thin and small copper sheet?
First, copper is a poor choice of materials to heat via resistance or induction. If you really need to heat copper, your best bet is conduction from direct contact with a heating element or convection from a heat gun. Steel that a magnet sticks to is your best bet for induction heating. Secondly, your question gives no indication of why you need to heat a copper sheet or blade. If for cutting foam or plastic, you might consider a hot wire cutter or a flat blade tip for a soldering gun. Heres one way to heat your copper using electrical resistance instead of induction.