Jim, I wondered if the coins you were talking about had iron content but, from looking at the composition, at least as listed here -- http://en.wikipedia.org/wiki/Coins_of_the_Canadian_dollar -- they should not be ringing in at 31, 31. If they are, something is seriously wrong or else you have iron/steel really close to where you're testing them. Looks like your loonie should ring in a little higher an American nickel (pulltab!) and your $5 somewhere below pennies, if I read that right. Yes, your pennies come in at 3-28. Same as American pre '82 pennies. I find them with some regularity. A U.S. clad (copper) dime tends to bounce around a litle higher for me than pennies usually do but not much. I'm finding the SE loves dimes for some reason though I'm still iffy at times in telling the difference from copper pennies. I'd guess I'm up to be able to tell the difference about 90% of the time, depending on the depth.