1993-D Lincoln Cent RPM

I think 89 was the last year mint marks were hand punched.

Split Plate Doubling is very common on Lincoln cents made of Zinc and plated with a thin layer of Copper.

The copper plating is very thin and the mintmark is very tall. The plating usually stretches around most design elements when the design is struck on it. It splits on the mintmarks more often than anywhere else. Once it splits or even gets scratched, air hits the zinc and the oxidation process begins. The zinc changes color and bubbles up. As it decomposes, it falls off the cent. At first it leaves pits, then craters, which in turn become circular holes. Eventually the cent becomes a memory.
Our mint wanted a cheaper cent, well we got one. Zinc just doesn't make a durable cent. Mint officials wanted to ease the public into it, so they put a cheap very thin layer of copper on it. I hope they've learned their lesson. Now they have to make more of them than ever. We lose money on all coins made, fortunately it's made up for by the bills printed.
I can't remember Ben Franklin's exact words, but he said the joy of a cheap price is far outlasted by the dismay of a cheap product. Here's an example of a cheap product in one of the later stages.

Your welcome Shotgung. I should have mentioned as RPMs exist only prior to 1990, copper plated zinc cents exist only after mid 1982. A couple of dates you'd do well to remember.

You bet EandV. I think we helped Shotgung some. We all help each other. It's a good thing there's a lot of us, we all need help from time to time.