Contributing Author: Anastasia Meredith Oh
Coins are made of copper and nickel because they are cheap.
A mint can made commemorative coins out of silver. This silver goes into a casting
furnace to be melted at 2100 Degrees Farenheight, and when it comes out
the silver is shaped into a long bar 5 inches wide, and 1.5 inches
thick. This long bar is then cut into a 30 inch long bar before it is
placed in a roughing mill.
The mill uses 9 tonnes of force to push the silver bar between 2 rollers which squeeze the bar so it becomes thinner. To make the bar 0.5 inches thick it may be passed into the mill up to 12 times. After this the bar
still needs to be reduced in height, so it goes into a finishing mill
to be made into the final height needed for the coin, which varies
depending on the design and denomination.