Error Other | '84 with extra thick rim

[ericodapro]

One side of this coin has a very thick rim but only on the obv, the rev rim is normal. It is over twice the size of a normal rim. Im not familiar with what this is called. Is this a planchet error or some kind of MAD?

[mustbebob]

Most likely either a tapered planchet, or a misaligned die.

[mikediamond]

You have a very slight misalignment, but this vertical flange can develop without a misalignment. It's called a "finned rim" and it results from excessive ram pressure or increased effective striking pressure at one pole caused by a slight bit of die tilt. Since your fin is restricted to the right side, the latter would seem to be the cause.