Coins
Mexico had had a mint since 1536. Macuquinas, or ‘cobs’, were made by cutting a silver bar into pieces of the appropriate weight and then striking a design onto them with a hammer and die. The cobs’ irregular shape made them susceptible to the common practice of clipping.

‘Cob’ 8 reales, Philip III (Mexico, 1610) (Image via Heritage auctions)
But in the 1730s, coins were introduced whose blanks were made on a milling machine to ensure a consistent weight and size. Their edges were also raised with serrated edges, a security feature making it was easy to tell if metal had been shaved or clipped off.

Charles III ‘pillar dollar’ (Mexico, 1771) and Charles IIII portrait dollar (Mexico, 1798) (Images via Heritage Auctions)

An 1853 Mexican ‘eagle dollar’ showing a chop mark
The Manila galleon came to an end in 1815 with the advent of the Mexican War of Independence. In the 1850s, the Mexican ‘eagle’ dollar was formally accepted as a substitute.