of what is produced on the coin. Therefore, the flush surface bearing the circles would be in recess on the die. Please explain how its possible to 'polish' this.

BTW - Stainless steel bar costs about 1/2 the price of sheet to produce (by volume) and wastage on cutting discs would be maybe 25%. Punching from sheet would waste 65% minimum and you cant recycle the waste so its more expensive than cutting wafers.