Top 6 American Manufacturers of Coins

Three types of coins are produced by the U.S. Mint — circulating coinage, bullion, and collector (numismatic) coins. The Mint then houses four production centers: The buildings in Philadelphia, Denver, and San Francisco handle machinery qualities while the one located in West Point deals with another type of process. Here we will tell you how the Mint makes coins.

You can read “Anatomy of a Coin” to learn about coin terminology and different types of finishes, such as proof and uncirculated coins.

The Manufacturers of American Coins

When the Secretary of the Treasury approves a design, the Mint’s medallic artists turn that line drawing into a three-dimensional sculpture. When the sculpture is finalized and digitized, the Mint creates coin dies to imprint the design on the coins.

Step One: Blanking

Blanks are flat metal disks that will eventually be made into coins. The Mint makes blanks for the following coins:

• Nickels
• Dimes
• Quarters
• Half Dollars
• Dollars

The Mint buys blanks for pennies, numismatic coins, and bullion coins.

To make blanks, the Mint buys 1,500-foot-long coils of various metals that are made to the exact specifications for each coin classification. First, the coils are passed through a machine that straightens the metal, and then they are sent to a blanking press. The puncher punches out blanks at a rate of 14,000 blanks per minute, like a cookie cutter. They have slightly different diameters, but the same thickness as a finished coin.

The blanks are moved to an annealing furnace for the next step in the process. Weighing 192 pounds each, the coils go for scrap at OmniSource in Jackson and then are cut and made into webbing.

Second Step: Annealing

The blanks are placed into annealing ovens in order to be prepared for striking. As far as the properties of metal are concerned, annealing alters these physical attributes to enable the same material to be easily shaped without destroying it. Annealed blanks can hold designs better when they are struck.

In the annealing furnace, the blanks are heated to 1,600 degrees Fahrenheit in an oxygen-free environment. The lack of oxygen prevents the metal from staining. They are then dropped into a tank filled with “slippery” water to rapidly lower the temperature. This slippery water is a mixture of water, citric acid powder, and lubricants that prevent the blanks from sticking to each other.

Next, the blanks are actually raised out of the tank. To form the capitals, blanks are fed one by one into a cylindrical drum called ‘Whirlaway’ which rotates them while gingerly lifting from water. The Denver Mint uses a big scoop, one called a “skip basket.” Empty blanks are transferred from the tank to the washing area.

Also Read: 3 Bicentennial Quarters That Will Blow Your Mind!

3rd Step: WASHING AND DRYING

The blanks are then washed to return them back to their original color. The cleaning solution combines a cleaner with an anti-tarnish.

The dryer dries the cleaned blanks before they move on to the upsetting mill.

Step Four: Upsetting

Distressing is a method of upsetting the coin or in others words rocking up the notsalged outer edge and making it a higher rim. The upsetting mill pushes the blanks into a groove just slightly smaller than its diameter. This pushes up the metal around the edge to form a rim. The rim protects the coin from wear and makes it stackable.

A blank with a rim is now called a planchet. Some people continue to refer to the pre-strike coin simply as a blank.

Most of the blanks purchased by the Mint are planchets ready for striking. When the Mint receives a shipment of planchets, inspectors check them carefully to make sure they meet the required specifications. Next, the penny planchets are sent directly to the press for striking.

Special proof and unstruck planchets go through a cleaning process called burnishing. They are placed in a drum with a cleaning agent and tiny metal pellets to smooth and polish the surface. An employee then dries the boards and towels.

Step Five: Striking

The planchets get sent to the coin press where they are struck with a design. While the Mint has different types of presses, they operate in a similar fashion. The press then smashes the topper and reverse dies into the planchet’s surface, allowing it to produce a complete Press for circulating coins using 35 to 100 metric tons of pressure, depending on the coin’s classification. Other presses strike with up to 540 tons of force, which is used to make America the Beautiful five-ounce silver coins.

Once the mold comes together, the sheet metal flows into the design. A collar placed around the planchet prevents the metal from spreading too much. It also shapes the edge design, whether it is smooth, reeded, or lettered. Dollar coins get a smooth edge from the collar, but they are then passed through an additional machine that rolls the letters onto the edge. Once the planchet achieves the design, it becomes a coin.

The circular coin press can press 750 coins per minute. If all 63 presses at the Philadelphia Mint were in operation, they could make 47,250 coins per minute. The Denver Mint has 54 mints with a production capacity of 40,500 coins per minute.This results in millions of circulating coins every day.

Coins are struck differently depending on their finish. Circulating, uncirculated, and bullion coins are struck once. Proof coins are struck at least twice. Circulation coins are struck by presses faster than other coins.

Once the press strikes the coins, they fall into either a bin or tray. An inspector checks the samples for errors. If they pass inspection, they are sent for packaging. If the circulation coins do not meet certain standards, the entire lot is sent to a machine called a waffler. The waffler bends the coins to form wavy lines and they are sent for recycling.

Step Six: Bagging and Packaging

When the coins pass inspection, they are counted and weighed. After passing through the counting machine, the coins are put into bulk storage bags. All bags are weighed and then stored for delivery to Federal Reserve Banks for distribution across the country.

Collector (numismatic) coins are packaged by robots and automated machines into blister packs, lenses, and other packaging so they can be sold to the public. Some coins are also packaged by hand at the Philadelphia and Denver Mint Centers. Bullion coins are packaged in 500-coin “monster boxes” and sent to authorized dealers.