In the Wiki article of Canadian coins the table lists the composition of each. According to this table the nickel is 94.5% steel, the dime 92%, the quarter 94% and the 50c is 93.15%.
Assuming this is accurate (it is Wikipedia after all) why is there these slight alloy variations? Wouldn't it be easier to make "silver" coins of the same alloy and just cut the planchets to fit?
I could see that there could be variations on the weight percentage of the plating material but these tables show the interior alloy being different. I assume also that they are plated after cutting but before striking.