David Lange explores the third side of the coin — the edge! In particular, he discusses why reeded edges play such an important role in U.S. coinage.
All United States coins have three sides, though often little attention is paid to the third side — the edge. The edges of coins have been important only in modern times, this being defined as roughly the past 500 years or so. Ancient coins, while they often had thick edges, were coined by the hammer and anvil method, making the application of an edge device impractical. Medieval coins typically were quite thin, leaving no space for anything on the edge. To prevent clipping (the practice of cutting or filing away some precious metal from the perimeter of a coin), die cutters sometimes included border elements such as dots or denticles. If these were not visible on a coin, it would theoretically serve as a warning to the recipient of that coin that some metal had been fraudulently removed. In actual practice, so many coins were struck poorly centered that these elements often were lacking as made, and clipping remained a common activity for centuries.
Clearly, a more reliable protection against clipping was needed. The advent of the screw press, which was adopted by nearly all mints of the western world during the 16th and 17th centuries, resulted in coins that were more uniform in dimension and centering. Such coins could also be given an edge design by running the planchets through a rack and pinion device prior to striking. The thicker gold and silver coins typically carried edge lettering, usually a Latin legend of some significance to the nation that minted it. Perhaps the most famous of these is DECUS ET TUTAMEN ("an ornament and a safeguard"), used on many British coins, including the current one-pound pieces. Any attempt to steal metal from the edge of the coin will be revealed by the loss of this lettering. Smaller silver and gold typically had engrailed or reeded edges, as these devices could be imparted to even the thinnest of machine-made coins.
The U.S. Mint has employed a reeded edge on nearly all silver denominations, though there exist notable exceptions. All of the gold issues carried reeded edges until the introduction of new Eagles and Double Eagles in 1907, these coins having distinctive edge devices that did not include reeding. All edge devices were omitted from the base metal minor coins after 1795, since these were not subject to clipping. Reeded edges persist in our current dimes, quarters, and halves, even though they serve no useful purpose on coins that lack intrinsic value. They survive only for the sake of familiarity and tradition.
Modern coins have their reeding imparted at the moment of striking, rather than in the separate step described above. The inside diameter of the collar features this reeding in negative, and the edge of the planchet receives this impression at the same time that the obverse and reverse dies are raising the design. Reeded collars were employed at the U.S. Mint at least as far back as the 1820s, these replacing the plain, open collars used previously.
The number and size of reeds for each denomination is not written into law, and therefore the individual U.S. Mints are free to manufacture reeded collars in-house to their own specifications or order them from outside vendors. The former seems to have been the most common practice, though there are records indicating that collars were sometimes produced at the mother mint in Philadelphia and then shipped to the other facilities. For the numismatist, reeding can be a very useful tool in the detection of counterfeit and altered coins. For example, it has been known for decades that the rare Carson City Mint dimes dated 1871-74 have 89 broadly spaced reeds on their edges, while the common Philadelphia Mint dimes of those years have 113 narrow and closely spaced reeds. Therefore, an 1874-CC dime having narrow reeding must also have an added mintmark.
Certain reeding variations have been promoted within the coin hobby, an example being the "fine reeding" variety of the 1876-CC quarter dollar. Though the 153-reed edge is more common for this date than the standard 113-reed edge, the fact that it is unique to 1876-CC may result in a premium price. Another such popular coin is the 1921 Morgan dollar, having 157 broad reeds. Known alternately as the "wide reeding" or "infrequent reeding" variety, this commands a premium over normal coins having 189 reeds on their edges.
About 25 years ago I was asked by a neighbor to appraise his coin "collection." Mostly just an accumulation of coins retrieved from circulation during the 1960s, it included several hundred Roosevelt dimes. Bored with the task of looking through this junk silver, my attention was captured by the fact that there were at least two r