Most (or was it all, don't remember) of their coins are now steel cores, with multilayer electroplated surfaces, including pure nickel on some. Even the new canadian penny is steel, with a copper electroplate...
This is also the case now in the UK and, when they first began to
use steel cored coins, I used to have fun ‘proving’ to people in the
pub that their coins must be fakes with a magnet - everyone knows
copper coins can’t be magnetic don’t they? Another such amusement
was suggesting to these people that I had ‘invented’ a marvellous new
copper-attracting magnet alloy - its amazing how many wanted to
invest in its development!!
Ian W. Wright