The reason the coins are jagged dates back to ancient times.
Especially before the handover of paper money, coins used in shopping included gold and silver. as in any era, some crooks in that era scraped these coins from the edges, accumulating these precious metals, albeit in a very small amount, and were able to use the money again. at that time, traders weighed money and did not accept it if its weight was missing. of course, you had the money. if you pay attention to ancient money catalogues, you will find that most of the coins are not fully rounded.
In order to solve this problem and protect the public from missing money, the edges of the coins began to be serrated. thanks to these serrations, it was immediately obvious that the edge of the money was engraved, and no one took the engraved money. this tradition has continued to the present day. although there is no longer a valuable mine in it, our coins have either a serrated or an inscription on the edges.
The first coins were not produced by molds, but by minting. in other words, the molten mine is measured in a certain volume and dripped on a surface when that melt spreads on its own, it would take a round shape. after that, when the mine was still at a temperature suitable for forming, a female would be placed on the seal and taken shape by beating another seal on it. in this case, it would expand in all directions with the impact on the mine, which was already close to the round. and the figures were not in the full money, but just in the middle. of course, in the meantime, the thickness of the coin was not a full round of coins due to impact effects, etc. depending on this technology, it must be quite difficult to make a shape other than a round, as the mint expands the money in all directions.
This system has been preserved for very long periods of time. the technology developed to prevent coins from being serrated from the edges of their mines is relatively recent. let's note that this technology with a little ear fullness lasts for us, for example, until the printing of mecidiyes during the time of abdulmecit.
So why have different shapes never been tried next to the round in later periods?
I can think of some answers, although some are coercion:
- Even if the corners are rounded, they can wear out quickly.
- The fact that all coins are in the form of a narrow cylinder allows the coins to be distinguished from each other just by looking at the diameter of the money.
- Portraits are more suitable for round shapes.
- It is very important that newly minted money is accepted by society. that's why we're being conservative about shape.
I pictured this procedure in my head. it is possible that the mines are also pouring into thin cylinder molds. but then it will be a problem to carry on the seal before it is beaten and still in a soft state. dripping the mine directly onto the seal is also not possible for reasons such as overflows to the edge, not being fully centered. therefore, the most logical solution seems to be to first cool the mine on a flat surface. in any case, the mine between the seals will expand in all directions as a result of the impact, which gives it a shape close to the round.