Modern coin production is a highly automated and precise process involving several key stages. Here’s a breakdown of the steps:
- Blanking: Giant coils of metal, designed for specific coin denominations, are uncoiled and fed into a blanking press. The blanking press punches out flat metal discs, resembling large cookie cutters, at high speeds (e.g., 14,000 blanks per minute at the U.S. Mint). The scrap metal left over is called webbing and is recycled.
- Annealing: The blanks are then heated in an annealing furnace to temperatures like 1,600°F (871°C) in an oxygen-free environment. This process softens the metal, making it more malleable and easier to strike without cracking. After heating, the blanks are rapidly cooled in a quench tank containing a special solution to prevent sticking.
- Washing & Drying: The cooled blanks are thoroughly washed to restore their original color using a cleaning solution and then steam dried.
- Upsetting: The cleaned blanks are fed into an upsetting mill. This process creates the raised rim around the coin’s edge by pushing the metal up as the blank passes through a narrow groove. This rim protects the design and makes the coins stackable. Blanks with this rim are called planchets.
- Striking: The planchets move to the coining presses where the final design is imprinted. Two dies, one for the obverse (front) and one for the reverse (back), are pressed together against the planchet with immense force (35 to 100 metric tons for circulating coins). The metal flows into the recessed areas of the dies, creating the raised design on the coin. A collar around the planchet prevents the metal from spreading excessively and also forms the edge design, which can be smooth, reeded (grooved), or lettered. Circulating coins are struck once, while proof coins (collector’s editions) are struck at least twice for a more detailed finish. A single coining press can strike hundreds of coins per minute.
- Quality Control and Inspection: Once struck, the coins undergo a rigorous quality control process. Automated systems and human inspectors examine samples for errors or defects. Coins that don’t meet the standards are typically marked (e.g., bent or waffled) and sent for recycling.
- Counting and Packaging: Finally, the accepted coins are counted, weighed, and packaged for distribution. Circulating coins are put into large bags for shipment to Federal Reserve Banks. Numismatic (collector) coins, and bullion coins are packaged more meticulously, often using automated machines or even hand packaging for specialized finishes.
This multi-step process ensures that the coins we use every day are not only visually appealing but also durable, consistent, and secure.
How does a coin get created?
Good point! Every minute the mint workers know they’re coming because the machine makes this fun little noise as they get pumped out by the bucket load. But that’s not the only thing it’s pumping.
How much does it cost to mint a $1 coin?
I can help with that. Overall, the seigniorage per dollar issued across all denominations of circulating coins from the U.S. Mint was $0.26, a 4-cent decrease from 2022. These costs cover everything from raw materials to facility costs, minting labor, and other direct costs.