Die Axis

Die axis refers to the relationship of the orientation of the obverse side of the die as compared to the reverse side of the die. Take a coin between your fingers with one on top and the other on bottom of the coin and rotate it like it was the globe. If the obverse side started right side up, depending on how the reverse is oriented is the die axis. As a test, most modern coins, including all US coins, will end up with the reverse side exactly upside down. This is called "standard coin rotation". Some people describe die rotation as per a clock face. The obverse always starts as 12:00. If the reverse ends upside down as in standard coin rotation, it can be described as having a 6:00 die rotation. This can also be described in degrees as an 180 deg die rotation. If when the coin is rotated and the reverse side is straight up just like the obverse side, this could be called "medallic rotation". This can be called either 12:00 die rotation or 0 degree die rotation. Modern machine manufactured coins almost always are in one of these two orientations, barring accidents. The Romans used either hand held dies which could create coins at any die rotation or hinged dies which allowed for more accurate standardization. Mints using hinged dies were able to mint coins at a particular rotation, give or take about 10 degrees. In examining my coins I prefer to evaluate the die axis with the coin in a coin flip. Often an ancient coin is not perfectly round and it is easier to accurately rotate the coin in a coin flip than in your fingers. When a coin reverse is not either straight up or straight down, the die axis can be described either as a clock rotation or in degrees. If the coin reverse points to the right, at 3:00 it would also equal 90 degrees. If the coin reverse points to the left at 9:00 it would equal 270 degrees. Any other orientation can be described in this manner.

Examples: