Are pennies surfaces flat

Answer 1

I'm not quite sure what you mean.

The blanks, or "planchets" from which all coins are struck are initially flat. They're punched out of huge rolls of metal in the same way a baker uses a cookie-cutter on flat dough. The blanks then go through what's called an "upsetting" machine that squeezes them slightly to put a raised edge on the planchet. Then the blank is fed into a press that strikes the front and back designs. If a coin also has edge lettering (e.g. the Presidential dollars, EU €2 coins) there is one more step, where the coin is fed through a machine kind of like the upsetter that presses in the edge lettering.

Because so many cents are struck at such high speed, there's a lot of variation in thickness and evenness of the final product compared to other denominations, if that's what you're referring to.