Doubled die

[3] These new single-squeeze doubled dies have slightly different characteristics than ones from the previous method, leading to different opinions on whether the class system has to be revised or not.

Modern coining methods have vastly reduced the frequency of these varieties due to the use of a single squeeze hubbing method during die creation, but doubled dies in modern United States coinage are still occurring.

But it has been discovered that the pressure created is so great, that some dies tend to slightly rotate during this process.

The 2004 Peace Reverse Nickel shows doubling in the date, motto, designer initials and eyelid of Thomas Jefferson.

The 2005 Bison Reverse Nickel, shows slight doubling in the word "Liberty" and in other devices of the coin.