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The E-Sylum (9/15/2013)

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The fourth article in a series about the Philadelphia Mint by Darrin Lee Unser has been published on CoinNews.Net. It has LOTS of great pictures - be sure to read the complete article online. Here's a brief excerpt. -Editor

Philadelphia Mint Maximum-Work-Hub-Tonnages Sign My brother and I were treated to a special tour of the operations at the United States Mint facility in Philadelphia. We had planned this trip for some time so I had many preconceived ideas of what would be most exciting.

I’ll be the first to admit, the procedures related to hub and die making were not high on my list. Our father was a tool-maker so I expected this process would be familiar and, as such, not heart-pounding.

Much to my surprise, I was completely enthralled. It was not the mechanics of it all that was most inspiring. It was the people. Sure, the equipment is impressive. Yet more striking, those in the hub and die making area projected great pride in their work and that really forged a lasting memory for me. Actually, we found high levels of pride and dedication all around the place. But as I had not expected too much from this particular section, their drive turned it into a great time for me.

Everything starts from steel. Bars of the metal arrive at the Philadelphia Mint in 10-12 foot lengths, which are then cut into 42-inch lengths and stored until needed.

A Mikron CNC milling machine is used to cut hubs and dies. If it looks familiar, that’s because it’s the same machine that is used to create Resin templates for U.S. Mint artists who sculpt in clay. It generally takes 15-20 hours to cut a coin hub and 25-30 hours to cut a 3-inch die. These CNC machines are more efficient and can produce a better quality product than the retired Janvier Transfer Engraving Machines.

Philadelphia Mint die making

To read the complete article, see: How the Philadelphia Mint Makes Hubs and Dies to Produce Coins (

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