Also die wear. All devices on the die wear in one direction. Towards the closest rim.
Why? Because the metal is pushed outwards in that direction. That is why the die flow lines are in that direction. On your coin, the devices that are on the outside edge of the coin, they form straight lines towards the rim. If the devices are wider on the bottoms/tops of the devices, like on your coin. The form lines wider than the devices close to the rim.
