A continuing study of a Test strikes for US Coins.

Last month we discovered that Die Adjustment Strikes were actually Test strikes conducted by Press operators of the US Mint. (Throughout this article Die Adjustment Strikes will be abbreviated by "DAS") * Last months article can be ascessed through the Newsletter Archives located at the bottom of the Newsletter main page, look for the blinking star.

This month we will enter the 1900's, where most if not all US Mints Presses are powered by electricity, instead of steam. the introduction of duel and quad presses in the early part of the middle of that century.

Electric presses were much easier to start and shut off and produced constant power for the most part. Flywheels that produced the much needed inertia were easier to stop, though the presses retained the flywheel brake for the operator to use to stop the flywheel.

Instead of single die on a press, smaller denominations started using duel (2) and eventually Quad (4) die presses. Where either 2 or 4 coins could be struck by the single downward movement of the press. This certainly raised production rates of coinage, along with more for the Press operator to be aware of and do..

Unions eventually worked their way into the US Mint, replacing the so-called sweat shops of the past. With the introduction of Unions, better work conditions and salaries prevailed drawing more qualified employees into the US Mint.

Over the years we interviewed several Senior Mint supervisors, press operators from the Denver and Philadelphia US Mints. All had at least 35-45 years of employment and described Minting procedures of the past when they were broken in by senior employees. All were interviewed separately, and concurred that these Test strikes where made AND still being made for a number of reasons.

Whenever a different denomination die was changed on a press (ex: quarters to dimes), the pressure had to be reset and checked.

At the end a work shift, if there had been any problems with a particular press, the press operator would leave a note describing the problem for the next relieving operator. This incoming operator would fix the problem and need to check the coining pressure of the dies.

Eventually Unions won a contractual wash-up time for their employees at the end of the work shift ( 3-8 hour works shifts/ 24hrs a day), forcing press operators to shut off their presses. Incoming operators for the new shift would then need to inspect the press along with the Operating pressures.

Replacement of dies required "DAS" to check the pressure and strike of the new dies. though recently with the introduction of computers to the Mint and Presses. This can be checked and adjusted by most presses with computers.

Past myths of Die Adjustment Strikes:

1. The stopping of the press would cause a continuing slowing of the flywheel to produce weak strikes. *Truth: We found out that in the early part of the 1800's Flywheel brakes were installed on presses and Press operators would stop hand feeding planchets into the feeding tube when the press was to be shut off.

2. If a pile up of coins would occur under one of the dies of a duel/quad press. It would produce a weaker strike under the other dies.
*Truth: We were personally shown and interviewed several Senior Press operators, who all agreed this was impossible because to the enormous amount of pressure of the press. "38" + TONS of pressure on a copper/copper clad/silver planchets would be like striking a "grape" with a Hammer! I was actually shown a pile up of "40" Ike dollars that formed a cone shape mass of copper clad metal. The Mint Supervisor took a Micrometer and measured the last struck Ike dollar of that pile-up and it was still with in specifications. So if , 40 Ike dollars piled-up on top of each other , All massed into one huge piece of metal could not effect the striking pressure of the last strike. It was like the senior official stated earlier, like "striking grapes with a hammer".

Next month we'll discover the approximate populations of DAS Test strikes, Prices , Rarity and how to tell one from a filled die..

Till next month, good hunting!

return to the main news page | on to the next news story

All content in this newsletter is the opinion of the author and should not be taken as sound investment advice.