It is not a railroad rim, Can't remember where I borrowed this info, but here it is. The error is commonly called the “railroad rim” even though it is the edge, not the rim, that is affected because it looks like a railroad car wheel. This coin exhibits a split-level edge where the obverse (hammer die strike) has expanded larger than the reverse (anvil die strike). This occurs when the collar jams on the shaft of the anvil die at a position where only part of the planchet is contained in the collar. Care should be taken not to confuse this error with a coin that has been damaged by being forced into a “lucky” coin holder. The partial collar strike has two distinct diameters.
Although you didn't say what the denomination is, it looks to be the edge of a 50 Euro Cents coin that was struck with a partial collar. The alternative is a coin that was jammed into some sort of bezel and then removed. If it is a coin such as the first one i described, it would be a partial collar error and it would be called a "railroad rim" although usually the portion of the coin without the reeding would form a larger flange. Since I am not 100% familiar with the coin presses used for the Euro coins, I can't be 100% sure without the coin sitting in front of me but I lean toward the partial collar (railroad rim) scenario. Thanks, Bill
