Things You'll Need
Instructions
Place the coin on the flat surface of your anvil.
Light your propane torch and direct the blue flame onto the coin until it becomes red with heat.
Pound the coin with the flat striking surface of a sledge hammer squarely and evenly. The heated metal coin expands outward in all directions, becoming more and more flat with each strike.
Cool the hot metal coin by submersing it in water when the desired flatness has been attained, this will also harden the metal.