Why do coins have serrations ( or grooves ) around their edges ?
To understand why many coins have edge serrations we must go back to a time before coin making-machinery was available .
From the first millennium BC , when coins were invented , up to the 17th century ( roughly ), coins were hand hammered by skilled artisans . The process involved placing a blank piece of metal between two engraved punches and hammering the top punch several times to imprint images on both sides .
Because the metal splayed out under pressure from the hammer strikes , early coins lacked a uniform edge . Even when coins were pressed into metal sheets and then cut out , the results were far from perfect .
GRESHAM ' S LAW
In an era when gold and silver pieces were in circulation , this characteristic made them vulnerable to ‘ clipping ’ - the act of illegally filing or shaving off a small amount of precious metal for profit .