The ratios and purity of the coin metals varied considerably. Most Chinese coins were produced with a square hole in the middle. This was used to allow collections of coins to be threaded on a square rod so that the rough edges could be filed smooth, and then threaded on strings for ease of handling.

What currency has a hole in the middle?

yen coin Like the five-yen coin, the 50-yen coin can be easily distinguished by the hole in the center.

Which countrys coins have holes in it?

Coins were also minted with holes deliberately in them. Frances 1921 25 centime had a hole as well as Japanese coins like 5 and 50 Yen. The most famous coins minted with a hole were Ancient Chinese coins that had squares cut into the centre instead round shape.