Coin Dies (The Short Story)

[WoodenJefferson]

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Plaster model approx. 8 inches in diameter. The plaster model is then covered with rubber to make a rubber mold which is then cast with epoxy to make a shell. This process has replaced the “galvano” method of producing the shell.

 

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Master Hub. (“Janvier transfer reducing machine” which traces the raised design in its reduced size to the steel master hub)

 

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MASTER DIES (Hundreds of incused design Working Hubs could be produced from the single Master Die.)

 

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WORKING HUBS (Each raised design Working Hub could then be used

in the hubbing press to produce hundreds of Working Dies.)

 

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WORKING DIES (Actual incused design dies that will be used to press the coins)

 

 

The average die life in the past had been somewhere around 600,000 coins to 1,000,000 coins. Improvements in die steel have allowed modem dies to strike up to two million coins and often even more than that. Despite the improved die life, thousands of dies would still be needed to meet the coinage demands for each denomination in a given year.

[RWB]

A mechanical reducing lathe is no longer used. Modern computer tool systems use lasers to measure depth and texture, then cut the master die.

[PerryHall]

Don't they also hard chrome plate the striking surfaces of the dies?

[michael]

yes they hard chrome plate the dies when striking proof coins

 

well the usa mint in philly does