1942 S Mercury Dime

So, can you explain this to me? How is this doubling acheived or created?

Fred

Fred-

I'm not an error-coin specialist, but I can tell you that mechanical (machine)
doubling or strike doubling is caused when a normal die "stutters," or strikes
twice (or more) when it interfacese with the blank.

Die Doubling is caused by a die that has the doubling in the die. These are
the classic and more valuable types of errors. A change in the die-making
process has eliminated the possibility for this type of error in post-1995
coins.

Regards,
Tom

Thanks Tom,

I will keep it or maybe it will be the subject of an RCC Contest in the
future! I still think its neat because of the prominent doubling that can
be seen. And what a surprise to find it in a circulated roll or Mercs!

Fred


"WinWinscenario" wrote in message
...
So, can you explain this to me? How is this doubling acheived or
created?

Fred

Fred-

I'm not an error-coin specialist, but I can tell you that mechanical
(machine)
doubling or strike doubling is caused when a normal die "stutters," or
strikes
twice (or more) when it interfacese with the blank.

Die Doubling is caused by a die that has the doubling in the die. These
are
the classic and more valuable types of errors. A change in the die-making
process has eliminated the possibility for this type of error in post-1995
coins.

Regards,
Tom

"Fred" wrote
So, can you explain this to me?
How is this doubling acheived or created?

This is something that every serious collector knows. The information
is out there in books. ("It's the kind of information they hide in
books." is the line from the movie LAKE PLACID.) The periodicals,
Coin World especially, run articles about this every so often. The
Error Collector Websites have informational articles, also. (Use
Google to call up a long list of hits, including CONECA, at
www.conecaonline.org/ I just wrote up The Double Die Collector's Club
website for my January column.)

This is the "easy answer" but not the "whole answer."

A working die is made from a hub. The hub as a positive image of the
coin. It makes a negative image in the working die. The hub is
pressed into the working die. The pressure hardens the working die,
so it must be annealed (heated to be softened). And the process
repeats. If the hub is not perfectly aligned with the working die,
the result is a doubled die. This can also happen from the same
process when the hub is created from the master die. The original die
must be pressed into a steel blank to make the hub from which the
working dies are make.

There are other kinds of doubling and other errors. In the 19th
century, especially in the early 1800s, the major devices (Liberty,
the Eagle) were hubbed, but the letters, numbers, etc., were punched
into the dies by hand.

There is more, much more.

Just to point to the depth of information... Technically (...
TECHNICALLY...) doubled dies are extremely rare today because the
servo-controlled indexing mechanisms are accurate to within a micron
and repeatable to within two microns. This technology goes back to the
mid-1980s. However, doubled dies are known in modern coinage. The
sheer volume of work ensures that mistakes will happen.