How the Philadelphia Mint Makes ATB 5 Oz Silver Coins

This sixth article about our visit to the U.S. Mint at Philadelphia includes photos and videos showing how America the Beautiful Five Ounce Silver Coins are made.

Half of the nation’s coins for circulation are made at the United States Mint facility in Philadelphia, but it also makes products for investors and collectors like the America the Beautiful Five Ounce Silver Coins.

I was captivated by how the three-inch coins are produced from a single multi-stroke press. It operates so much differently than the Philadelphia Mint’s more than 60 presses that make circulating coins. Enter the impressive German-made Grabener 1000 press, capable of striking 40 coins a minute with up to 1000 tons of pressure.

America the Beautiful three-inch coins are offered in an uncirculated quality for collectors with a "P" mint mark, and a bullion version for investors. As a touch of perspective, for this year and as of today, this one coining press has resulted in United States Mint sales of:

• 110,000 coins, or 550,000 ounces, in investment-grade America the Beautiful Five Ounce Silver Bullion Coins.
• 67,468 coins, or 337,340 ounces, in collectible America the Beautiful Five Ounce Silver Uncirculated Coins.

Let’s get to how it all happens…

How 3" America the Beautiful Silver Coins Are Made

To begin coining, operators place three-inch planchets into black holders so they fit snugly on the presses’ continuous conveyor system. These planchets are purchased ready to strike, with each already upset, annealed and sonically cleaned.

Five ounce silver planchets travel inside the coining press by conveyor, which is shown stationary in the video and two photos below. When the press is running, planchets move continuously around the conveyor just like luggage on an airport’s baggage carousel.

When the press needs a planchet to strike, a robotic arm with suction cups grabs one from the conveyor and places it into position.

In the main pressing area, a heads or obverse die is anchored. These dies, which are also made by the Philadelphia Mint, bear negative designs so they can create the positive coin image. The obverse die serves as the anvil or stationary die. This piece has the large image of John Flanagan’s portrait of George Washington along with surrounding inscriptions of UNITED STATES OF AMERICA, LIBERTY, IN GOD WE TRUST, and QUARTER DOLLAR.

A three-piece collar surrounds the die. On one of those pieces, an edge inscription reads .999 FINE SILVER 5.0 OUNCE. This will be incused into the edge of the coin at pressing time.

In vertical alignment to the obverse die is the reverse hammer die. It has the reverse or tails image of the coin along with the inscriptions of the site name, its location (state or territory), the year of minting and E PLURIBUS UNUM.

As a blank planchet is fed into the collar, the reverse hammer die is hydraulically driven down with incredible pressure toward the obverse anvil die. The metal from the trapped planchet flows between the two dies, transferring the designs and creating the coin. Out from the front of the press slides a freshly minted America the Beautiful Silver Coin. At the same time, another planchet is slid into position for striking.

At a rate slow enough to watch, yet still quite fast, the following video shows a planchet sliding into position for three strikes. The resulting new silver coin falls down a chute and onto a waiting pallet.

Here, photos show the inner components of the coining press as seen in the video.

This process is fascinating with all the internal movements and activity. Watching shiny America the Beautiful Silver Coins slide down in front of you is something you just don’t forget.

Collector Uncirculated Silver Coins are Vapor Blasted

Collector America the Beautiful Five Ounce Silver Uncirculated Coins are pressed exactly like the bullion versions, but there are some differences.

To start, dies placed in the Grabener press for the uncirculated coins are more polished, and the obverse die has the "P" mint mark. Also, after the silver coins are created they are moved to another machine for vapor blasting. This process removes the brilliant finish that is kept for bullion coins and creates a consistent coin-to-coin matte finish for the uncirculated coins. To achieve this matte finish, the machine "blasts" the silver coins with a water vapor and ceramic media mix. The process is like sand blasting but instead of using dry compressed air the machine uses compressed wet vapor.

You can see the difference. Photos of several uncirculated silver coins follow. Note how their finish is different from coins immediately out of the Grabener press. The first photo is of a 2013-P Mount Rushmore America the Beautiful Five Ounce Silver Uncirculated Coin. These are scheduled to launch in early November but the Philadelphia Mint in August was already building an inventory of them.

Before closing, we wanted to add one more video that we discovered during our research. This one, by the United States Mint, is a bit dated at over two years old but it still offers a nice overview on how America the Beautiful Five Ounce Silver Coins are made.

That’s it for this article. Thank you for visiting CoinNews.net and please come back.

Final Articles in Series About the Philadelphia Mint

Return Friday, October 4, for a short article that takes a quick look into how the Philadelphia Mint prepares collectible proof dies for making First Spouse Gold Coins. Then return Monday, October 7, for the last article in our series. This one offers final comments, and it’ll have every photo we’ve published.

Links to past articles about the Philadelphia Mint are found in the upper right of this page, directly below the Google map of the facility.