What Is Coin Annealing?

By GovMint :

Coin annealing is a critical process in coin production that involves heating the coins to high temperatures and then slowly cooling them. This method helps to soften the metal, making it more malleable for striking while enhancing the coin's durability. Annealing also relieves internal stresses within the metal, reducing the likelihood of cracking or deformation during the minting process. By carefully controlling the annealing process, mints can ensure that the coins have the right balance of hardness and ductility, resulting in well-struck and long-lasting coins for circulation.

Sources Used:

https://www.usmint.gov/learn/production-process/coin-production