Major error eye candy #8: Incomplete clip mystery dime?

jonathanb · March 15, 2014 12:10PM

An incomplete clip is formed when the blanking press fails to punch all the way through, creating a deep planchet-shaped indentation in the metal sheet. The sheet then advances partially and a second punch is successful. Coins struck on incomplete clips show a deep indentation on both sides, where the curvature of the indentation matches the curvature of the coin. This is an example of an incomplete clip:

This next coin is... something. I don't know what. It was described as a cud, which is definitely wrong. A cud is formed when part of one die breaks off entirely. There is a large raised area on one side of the coin where it flows unimpeded into the broken portion of the die, and a corresponding weakness on the other side where the broken die wasn't present to provide pressure. This coin shows weakness on the reverse side, but it doesn't show a raised area on the obverse, so it can't be a cud. What it does show is a deep curved impression that is very similar to what is seen on an incomplete clip. But in this case the curvature of the impression doesn't match the curvature of the dime. Also, there is weakness on the obverse as well as the reverse. And there isn't a matching curved mark on the reverse.

The weight is 2.242 grams, which is teensy bit light (should be 2.268 grams). I'm not convinced that little bit is significant.

Anyone have an explanation for what's happening with this one?

Earlier:
Major error eye candy #1: Edge strike, double struck
Major error eye candy #2: 125% struck through cloth
Major error eye candy #3: Struck through feeder finger
Major error eye candy #4: 1955 Double Date Lincoln Cent
Major error eye candy #5: Nonface strikes
Major error eye candy #6: Reeding struck through coin
Major error eye candy #7: Broadstrike with partial counterbrockage

seanq · March 15, 2014 2:48PM

It looks like part of the clad layer came off the obverse before the strike, possibly even before the rim was upset. The rim still struck up filly but the thickness was reduced just enough to weaken the strike. The weight ties into this theory as you would expect the coin to be very slightly underweight.

Sean Reynolds

jmcu12 · March 15, 2014 4:07PM

I have a quarter that looks similar - could the dime be a retained cud? I can't tell from the pic for sure.

jonathanb · March 16, 2014 2:41AM

I'm not sure I buy the idea of part of the clad layer coming off before the strike. The clad layer is really thin. It's hard to see part of it coming off. Even if part of it did come off, that wouldn't change the thickness to affect the reverse so drastically. And none of that explains the curved mark either -- or explains how the curved mark gets to be in the middle of the weak area.

A retained cud would show weakness on the reverse, but would show a raised area (not weak) on the obverse. And a retained cud also wouldn't explain the curved mark.

It occurred to me overnight that I could measure the radius of the curved mark, so I've done that. The lengths are shown in pixels in the image, and my math says that the curved mark would form a circle that was 1.64x-1.9x as large as a dime, or 29.3mm-34mm. A half dollar is 30.6mm, comfortably in that range. So maybe this was punched from spoiled half dollar stock, rolled too thin for the half dollar blank to punch out a planchet and then fed a second time through a dime blanking press? Maybe?

seanq · March 16, 2014 3:06AM

The new pictures show that my first thought was wrong. There is striking weakness on the obverse that matches the weak area on the reverse but does not match the area inside the curved line. The weak strike can be explained by a tapered planchet, but it doesn't explain the curved indent. Most confusing to me is the lack of a matching curve in the reverse, the strike is so weak in that region that I would expect it to be just as bold as the obverse had it been from a planchet punch. It is plain that the Mark was there before the strike and happened in the Mint, but I am at a loss as to how and why.

Sean Reynolds

jmcu12 · March 16, 2014 3:42AM

Agreed, now that I see a larger pic, it is not a retained cud. Hopefully Fred will chime in.

The thought of an incomplete clip half dollar and rolled thin to dime stock would be ultra cool!

errormaven · March 17, 2014 9:22AM

I suspect we're looking at pre-strike planchet damage.

By the way, I have a column on incomplete punch errors in the March 24 Coin World.

Major error eye candy #8: Incomplete clip mystery dime?

Comments

Leave a Comment