I'm looking here at a 1972D dime sitting next to a 2000P dime. I notice that the 1972 dime has a much larger overall obverse design. The head is noticeably larger, and as well, the word LIBERTY is almost touching the rim. Are these sorts of variations common in US coins? Where in the process does this variation happen? Was it intentional?
The designs are touched up/modified fairly regularly. In this case the obv design was modified in 2000 because the extrar width of the 2 and the three 0's meant that there was not enough room between the neck and the rim. So the head was made slightly smaller and at the same time the lettering was moved away from the rim The varieation occurs in the original model. A new model is created and then the new master hub is created from it. And yes they are intentional.
I have seen this happen for a lot of coins, particularly the Lincoln cent. Is it ever possible for this to occur mid-year so that there are different designs within the same year? TC
The 1982 Lincoln cent had several varieties, 7 if I'm not mistaken. They had large date and small date coins, copper and copper plated zinc and three different mints if you include the S proof.
As said already- yes. Now this was last updated in '98, but it will show you the answers you seek. http://users.scronline.com/lockem/20thcentury.txt