A “cud” is a type of die break in which a section of the die face and adjacent part of the die neck break off. This leaves a void in the die face. Every coin that is struck shows a featureless lump where the coin metal bulged into the void.
While all cuds are die breaks, not all die breaks are cuds. By definition, a cud must incorporate the design rim and at least a little bit of the field. If a die break is confined to the field, it is referred to as an “internal die break” or “interior die break.” Very small internal die breaks are called “die chips.” If a die break only carries off the design rim, it is called a “rim cud.”
Cuds are not die varieties. They are not present at installation and have no connection to the die manufacturing process. They are, instead die errors. Nevertheless, many people catalog them. Some cuds are dynamic, steadily growing larger as more metal breaks off. However, many are quite stable after they form, creating a basis for a cataloging system.
Sometimes a die fragment is held in place, either by the collar (which surrounds the anvil die) or by the bolts that hold the hammer die. A die fragment that is held in place usually sinks in below the level of the die face, creating a “retained cud.” A retained cud shows up on a coin as a raised plateau of metal that carries the design. A retained cud must show either vertical displacement, horizontal offset, or both. Simple lateral spread is not sufficient to diagnose a retained cud.
Cuds may develop quite suddenly, or may be preceded by lesser forms of die fracture. A cud is sometimes preceded by a “pre-cud die crack.” This is a crack in the die face that connects two points on the rim. A cud may also be preceded by a retained cud. On rare occasions, a cud may be preceded by an asymmetrical split die. It is always instructive when one can track down the stage that precedes the definitive cud.
All known cuds that break out onto the coin's field from the rim are listed here. Rim cuds are not included - at least for the time being.
A class of die cracks hereby called "Pre-Cuds" will someday be listed here (based on existing data at hand. These die cracks appear in the same place where a retained cud or a cud occupies at a later point during the coin production at the mint.
In the CUD table, each cud is identified with two different number codes. The first one comes from The Cud Book (1997) and The Cud Book Supplement (2001) both by Sam Thurman and Arnold Margolis. For the sake of briefness, each number code is stripped of its prefix, namely, "KHDC-".
The second number code given to each cud is called Universal Variety Code (UVC) by CONECA (www.conecaonline.org). According to Dr. James Wiles' The Kennedy Half Dollar Book (1998 edition, page 9), UVC is assigned to each variety "within a denomination and series."
Also listed in the table are each cud's clock position, maximum width and depth, both of which are given as approximate percentages of the diameter of the half dollar. The width is the straight-line distance between the two points where the cud's edge meets the half dollar's outer rim. The depth measurement is based on the deepest part of the cud with respect to the coin's rim. All of these figures are, at best, approximations.
Each cud's picture can be viewed by clicking on its CUD-number designation in the CUD table. By holding your mouse's cursor over the picture, you will find a small pop-up providing some additional information. When done with viewing, click on the picture to return to the CUD table.
As of today, the total number of cuds listed here is 24.
While most of cuds in the Kennedy Half Dollar series are of a crescent shape, much like that of a football, a note must be made here regarding a few cuds that are of a different or unusual shape. There are a few cuds that appear like a rim cud - running along the edge of the coin - and yet break out onto the coin's field. The 1984-P cud's shape is akin to that of an arrow head bisected in the middle lengthwise.
Please do feel free to report any findings to Ken here.
Many thanks go to Mike Diamond for his great help and input for the introduction to Cuds above.