It surely doesn't look normal. It has a an additional raised rim between the lettering and the edge beading. An incuse gutter could be achieved with a lathe and would be post mint damage, but this ring seems embossed.
Do the other dimensions (size, weight) fit with the original coin?
Sorry about the oversight about not having the link, future posts will.
the ring is raised(embossed) that is why I believe is is not post mint damage, I have not weighed it, I received it in a sealed flip. It appears to be the correct size though, I have another coin from the same year and seem to be identical otherwise. I will check the weight.
Dimensions are close enough, and the coin does look like authentic coin. These 20 penniä coins are not expensive, usually they don't cost like anything, just cents each, in Finland I mean. So why counterfeit, no rational reason. I believe it is some kind of strike error, but I have never seen that. I was wondering if that extra rim could have been added later? I will check my colleagues here in Finland if they have seen anything like this.
To me it's a very distinguishable variant and therefore it deserves its own year line. I don't believe this is an error, a result of an excessive striking pressure, as suggested on that comparable topic.
I agree.
I think the extra ring was made on the die by the engraver. He must have decided to do it, departing from the master.
there were thus two different sets of dies that made this coin.
Jamais l'or n'a perdu la plus petite occasion de se montrer stupide. -Balzac
That is not very rare, actually it is very common mint error in 1980's Finnish 20 penniä coins, based on my colleagues in Finland. I don't have any of these variants but my friend has some 20, different years. Some of these have extra rim only on reverse side some on obverse and like this one here, on both sides. Some coins have only partial extra rims, so if you are going to add this as a variant please notice that. That extra rim has been mentioned on one new Finnish cataloque (Holmasto), which I don't have yet. There is no information what has caused that extra rim, even though these coins are not that old.
