Most coin sorting machines employ a graduating rail or sorting disc system to file a group of differing coins into similar groups. Once a coin is inserted into the sorter, it is funneled past a series of increasingly larger holes. Once the coin finds a compatible hole, it drops into the coordinating compartment.
The most basic of coin sorters uses gravity to help filter coins into the appropriate slots. Manual coin sorters often use a hand crank to help line up the coins onto a rail system, which sorts the coins. Electronic machines use more complicated machinery, including motors, conveyor belts and computers, to execute the process.
Inexpensive at-home coin sorters employ a rotating disc to sort coins. The process of sorting creates a good deal of friction, which puts a motorized sorter at risk of overheating if overloaded or used for an extended period of time. Commercial coin sorters, which tend to be more expensive, use a high-speed motorized rail system.
Coin sorters feature holes specific to the sizes of a country's coin currency. As such, one model of coin sorter might not work accurately in multiple countries. Some coin sorters are also coin counters, using a computerized mechanism to calculate the value of the currency sorted.