1972 Lincoln Memorial Cent Cuds

These are called rim Cuds. What causes these?

When part of the rim crumbles away it makes the rim higher than the normal rim. (Note on the die on the front left. I made a simulation of a die with that area chipping away) Note also how the fin was not as flattened on that area because of the rim Cuds. So the tilted die may have some into contact with the collar and chips the shelf away on the die. What does a normal shelf look like?

People save them But think about it. The rest of the coins struck with that die (probably 60% of them unless the die is retired early) will show the same event and possibly get worse with time. You could save as an education piece to show two things. A rim cud and a fin on a cent. So you could show a new collector two things of interest on the same coin. A third item would be that the devices are smaller than normal on the obverse, from a polishing to remove a die clash. So you might save it to show a new collector what can happen on coins.