Debasement

The denarius continued to shrink in size and purity, until by the second half of the third century, it was only about 2% silver, and was replaced by the Argenteus.

[2] Debasement lowers the intrinsic value of the coinage and so more coins can be made with the same quantity of precious metal.

When done by an individual, precious metal was physically removed from the coin, which could then be passed on at the original face value, leaving the debaser with a profit.

Until the mid-20th century, coins were often made of silver or (rarely) gold, which were quite soft and prone to wear.

Modern coins used as currency are made of hard, cheap metals such as steel, copper, or a copper-nickel alloy, reducing wear and making it difficult and unprofitable to debase them.

Clipping is the act of shaving off a small portion of a precious metal coin for profit.

Over time, the precious metal clippings could be saved up and melted into bullion or used to make new coins.

Starting with Nero in AD 64, the Romans continuously debased their silver coins until, by the end of the 3rd century, hardly any silver was left.
A 16th or 17th century hoard of coin clippings discovered in Derbyshire and recorded in the Portable Antiquities Scheme .
Shears used for coin clipping in the 17th century
Modern example of a sweated silver coin