Definition: These concentric rings are produced by a lathe which shapes the cone-shaped face of the unfinished working die. The cone is supposed to be polished smooth before hubbing.
If polishing is omitted or inadequate, the surface will remain covered by concentric lathe marks which will not be erased by subsequent hubbing.
Concentric rings can be seen near the rim under the word TRUST down to the date.
Lathe rings seen on a 1984-P Lincoln cent.