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Convex Reverses on Kennedy Halves a First
 | By Ken Potter, Numismatic News
August 31, 2009 |
Pepe DeMeo of New York sent in a 2001-P Kennedy half dollar with some very interesting effects. While a normal coin has basined (concave) fields, the reverse of his coin is convex, somewhat like a brass button.
A normal concave effect allows the central design to be raised up from the recess to gain relief and still be lower than the rims to protect the designs from undue wear and to facilitate the stackability of the coins.
On DeMeo's coin, the area where it slopes down toward the rim the fastest begins at the circle of stars, though the field seems to actually begin its decent towards the rim much closer to center. Many of the stars that encircle the central design are connected by die stress cracks.
As a result of the convexity, the coin does not lie flat on the reverse rim but instead teeters on the uneven high points of the design, upon which it could actually be spun like a top.
For all practical purposes, the obverse is normal. DeMeo was able to find seven of them out of ten $100 face-value bags that he purchased from the U.S. Mint's Web site around July of 2008. He found four in one bag and one each in three other bags.
In the 30 years that I've been specializing in error and variety coins, this is the very first example I've seen of a coin with either the obverse or reverse bearing any kind of convexity of this sort.
So, other than the obvious fact that the die was breaking up, what does this coin represent? I sent my questions to Sean Moffatt of Moffatt & Company, a private mint located in Eureka Springs, Ark., and got the following answer:
The die was on the verge of a massive cud break or total failure. For this convex shape to happen the reverse die would have to be in the collar side of the press. The outside edge of the die had already began to break away and the pieces were probably wedged between the collar and the die, and were not re-seating completely in their original position during coining which would make them higher than the field which would make the edges of the coin seem to fall away, which is why the coin appears to be convex.
I have had this happen and either the collar will break allowing the pieces to fall out or the die would finally "explode" and all the pieces would fall out. Both have happened to me. It sounds like a 45 going off when a collar lets loose due to a cud break. The U.S. Mint should have been using a carbide insert collar by 2001, and when the carbide broke it would [have] shattered into pieces instead of cracking or breaking in to 2 or 3 pieces like a standard collar. The carbide could have withstood the wedging of the die pieces longer than a standard collar before breaking, which could account how this piece came into existence.
Moffatt was operations manager of Hoffman Mint for 19 years where he oversaw the production of more than 65 million units per year. He has attended several Mint Directors Conferences and numerous industry events, and he is thoroughly networked in the minting trade.
His educational background includes four years of electronics. He can design, build and maintain machine and industrial controls. He has experience as an electrician, machinery rigger/transporter, haz-mat transport driver, cryogenic filling plant technician and an electronics technician. He is proficient with AutoCAD for tooling design, facility design and plant layouts.
He has the mechanical ability to tear coining presses and support equipment down to the frame and rebuild or repair most all problems.
Moffatt & Co. was founded in October 2007 with former Gallery Mint chief coiner Timohy Grat. It specializes in high-speed production of coins, tokens and medals.
Ken Potter is the official attributer of world doubled dies for the Combined Organizations of Numismatic Error Collectors of America and for the National Collectors Association of Die Doubling. He also privately lists other collectible variety types on both U.S. and world coins in the Variety Coin Register. He is a regular columnist in Numismatic News' sister publication, World Coin News. More information on either of the clubs or how to get a coin listed in the Variety Coin Register may be obtained by sending a long self-addressed envelope with 60 cents postage to P.O. Box 760232, Lathrup Village, MI 48076 or by e-mailing at KPotter256@aol.com. An educational image gallery may be viewed at www.koinpro.com.
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