Abraded die varieties are created on the production line by the minters, the coin press operators. In the normal production of a coin, a planchet is fed onto the anvil die of the coin press. Then the hammer die slams down on it at tremendous speed and pressure, creating a coin. Sometimes, due to a machine malfunction, there is no planchet present when the hammer die comes down. This results in a “die clash”. There is no planchet to stop the hammer die so it hits the anvil die imparting a partial image of the obverse die onto the reverse die and a partial image of the reverse die onto the obverse die. Because the highest parts of the dies collide with the most energy, that is where the erroneous impressions are usually made. The high parts of the dies correspond to the low parts of the coin design, the fields. So, the next time these clashed dies are used to strike coins, the clash marks usually will be most visible in the fields of the coin, not on the devices.
If a die clash does occur, then the operator of the coin press must decide whether to remove the die from service, to abrade the clash marks from the die, or to continue to use the die with clash marks. Presumably, if the clash marks are large and/or apparent, then the operator decides either to discard the die or to remove the clash marks. If the marks seem relatively minor, then the operator may decide to ignore them (or may not even notice them) and continue minting coins with the clash marks being conveyed to the coins.
Removing clash marks from a die is not an easy task. The die is small and made from very strong tempered steel. If the die clash is in the middle of a field, then the operator can apply a lot of pressure as he abrades away the clash marks. And he can smooth out the abrasions, leaving a nice smooth field where the die clash had been. Because some of the die has been abraded away, the field may be a little shallower than before, but typically this is not a noticeable change. On the other hand, if the clash marks are close to a device or on a device, then the operator must be very careful. Sometimes, part of the device itself will be abraded away or greatly diminished. This is quite noticeable and is an Abraded Die Variety.
Ron Pope’s book, Buffalo Nickels: The Abraded Die Varieties (ADV) is the bible for Abraded Die Varieties. A total of 21 abraded die varieties of three different kinds are included on the CPG/PCGS varieties list. There are 15 Two Feather (2F), one Missing Initial (MI or No F), and five Three Leg (3L) or Three and a Half Leg (3HL) varieties. There are many, many other abraded die varieties. Pope’s ADV lists 29 2F, 28 No F, and seven 3HL or 3L varieties as well as several other kinds of Abraded Die Varieties! See ADV for the most extensive and up to date list and detailed information about each.