Qustion About Rotated Dies Nomenclature.

I don't know if there is a standard, but if a reverse is rotated 90 degrees CCW, it would be 270 degrees CW. Which sounds better? I assume you would use 180 as the max (up to 179 degrees CW or CCW), with no higher than 180 degrees period. That's my way of thinking anyway.

The reason the reverse is rotated is because the reverse die is usually the anvil die, the obverse the hammer die. Now if the reverse die becomes loose in the press, it wouldn't fall out but rather rotate in place as it is struck. Some Indian cents show a progression of die rotation. So for example you can find specimens from the same die pair with 5, 10, 15, 20, 25 degrees of rotation. A 180 degree rotation, or medal alignment, is probably caused by improper installation of the die in the press.

If the obverse, or hammer, die becomes loose then it will just fall out of the press. This scenario may have been what caused the off-center clashes on Indians in 1880, 1889, and 1890.

In the classics era, the hammer die was held in place by 3 set screws. We do have instances where one of those set screws came loose, but it doesn't cause the hammer die to rotate. Rather, the hammer die will become slightly titled in place as it shifts towards the space afforded by the loose set screw, and will not strike the coin on center or flush. These are called misaligned dies typically, and are often labeled that way on slabs. But they are VERY rare. I have only seen 2 in the IHC series, the finest of which I actually snagged off ebay from Rob.

I will be doing an article on this coin, and its 'sister' coin, in the coming weeks. The other coin shows an on-center and an off-center clash caused by misaligned dies. So it is the same exact situation that created the coin below, but without a planchet in the press.

http://www.ebay.com/itm/12149674446...RK:MEBIDX:IT

But I am interested to know how it is determined whether the die rotated CW or CCW. I mean, a 90 degree CW rotation is the same as a 270 degree CCW rotation. How can you tell the difference? I don't collect rotated dies so I'd be interested to know. Perhaps coins are not described as being rotated more than 180 degrees, and the CW/CCW classification tells you which direction the die appears off center when you view it.

Someone here knows!

First, the rotation is always assigned to the Reverse face. One places the obverse in a face-down position where the Reverse should be straight up, and measures based on that. I've seen the rotation described both ways - 180CW/CCW or 360CW - but CW/CCW seems to be the broader usage.

great explanation drsandman2, and I'm glad the 1863 MAD is in good hands!

Isn't this a great forum?