James Wiles states: "1991 – The U.S. Mint began punching the mintmark into the master die for the dime, quarter, and half dollar denominations. The last year possible for an RPM on a business strike dime, quarter or half is 1990" http://www.varietyvista.com/Watersh...U9aqXOxBpD8AUsAj4TU3UogwqDqUDGJh2h9hBBntxBjHU I asked him for the source of his information. He said that it was in all the numismatic publications at the time. Information came from the Mint. He suggests looking in back issues of the Numismatist, Coin World, etc. I do not have copies of any issues for 1989/1990/1991. I wonder if anyone would be interested in checking their library? I know all other sources that I am aware of claim that RPMs are not possible after 1989.
The Sixth and Seventh editions of the Coin World Almanac report this change in their "Review of the News" sections for 1990 and 1991, respectively. In the Sixth Edition, it states for 1990 that: On page 324, under the U.S. Coins - Mint Marks section, it also claims that the mint mark for all proof and commemoratives would be added at the plasticene model stage of die production. And that the procedure would be phased in for circulation coinage. In the Seventh Edition, it states for 1991 that: So, according to Coin World, RPMs for cents and nickels shouldn't be possible after 1989, and for all other denominations after 1990.
Good information - thank you! I just found this: “Elimination of Hand Punched Mint Marks on the Working Die. In FY90, the Mint completed a change within the die marking method with the mint mark on obverse work dies. Work dies requiring a mint mark were stamped manually in the past. Using the new method starting in FY91 {October 1 1991 begins the FY91}, the mint marks will be placed on the master die ensuring uniformity of mint marking on all circulating coins.” From Page 25, Annual Report of the Director of The United States Mint, Fiscal Year 1990, Donna Pope, Director of the Mint
I had step out for a bit, so I did not have time to peruse the Mint Report until now. If you back up just one page, there is clarification for you: So, this clarifies that the process would be implemented for the 1991 designs.
You added {October 1 1991 begins the FY91} which would be incorrect as the fiscal year is termed as the calendar year of the end of the term. So, FY91 would cover October 1, 1990 through September 30, 1991.
