Last year I had the opportunity to spend a couple days at the National Archives Region II in Maryland performing research for the new edition of my book about Mercury Dimes, which was published in July. In addition to discovering that two days were not nearly enough, I also came across an interesting item that has changed my way of thinking about die collars.
Ring Around the Collar...Part One
Last year I had the opportunity to spend a couple days at the National Archives Region II in Maryland performing research for the new edition of my book about Mercury Dimes, which was published in July. In addition to discovering that two days were not nearly enough, I also came across an interesting item that has changed my way of thinking about die collars. These are the steel rings that frame the upper and lower dies and form a coin's edge at the moment of striking. The opening in a collar may be smooth, as when striking cents, nickels and Sacagawea dollars, or it may have grooves to impart the reeded edges of dimes, quarters and halves. While coin dies traditionally have been made at the Philadelphia Mint and then shipped to the other facilities as needed (the Denver Mint opened its own die shop in 1996), the machining of collars has always been attributed to the mint at which they were used. At least, that's what the numismatic literature says, and I've often repeated it in my own writing.
To my surprise I discovered letters written by the Director of the Mint in Washington, DC to the Superintendent of the Philadelphia Mint instructing that the Superintendent have collars made and shipped to the various other mints, per their request to the Director. Here then is proof that die collars, at least those used during the years 1914-17, were machined at the Philadelphia Mint for use there and at the mints in Denver and San Francisco.
This correspondence was preserved in the form of "press letters." These are paper tissues that were set atop the actual typed letters, whereupon the two were compressed within a hand-cranked, rotary press that imparted a barely readable transfer to the tissue paper (You may have laughed as Moe, Larry or Curly placed some tough guy's head in one of these old machines, which, needless to say, are museum pieces today). These flimsy press letters are now bound together, thousands of letters to a single volume, in the Maryland research center.
Particularly of interest were the several references I found to the three-piece, segmented collars used for coining Saint-Gaudens double eagles. Examining the edges of this coin type you will find three raised lines running at right angles to the coin's obverse or reverse. These are the parting lines where the three pieces of the retractable collar met one another at the moment of striking.
Another interesting tidbit that turned up is that the mints received more than one size of collar for the same denomination of coin. Of course, the inside diameter of a collar had to be constant, as it determined the diameter of the resulting coin, but the mints utilized collars of differing outside diameters. These were provided so that the mints could employ whichever presses were available when a particular denomination of coin was needed. Thus, cents could be coined on either a small press (as was the norm) or a large press that was fitted for a larger collar.
Until the 1820s the United States Mint appears to have used collars solely for centering planchets as they were placed upon the lower die. These were known as open collars, since they did not actually compress the coin during the striking process. Whatever edge device appeared on a coin was imparted in a separate operation, prior to striking. Most literature, including my own book on the history of the United States Mint, asserts that it was not until 1828 that USA coins were struck within close collars that actually formed the coin's edge (these are the Small Date dimes dated 1828). Recent research, however, has revealed that certain dimes and quarters display repeating collar flaws that establish usage of the close collar earlier in the 1820s.
Though the advantages of using close collars over open collars were many, including uniformity of diameter and raised rims that protected a coin from wear, they did present a new set of problems for the mints to overcome. These collars had to be aligned properly with the obverse and reverse dies to avoid what U.S. Mint personnel called "finning." This phenomenon is better known to the coin hobby as a "wire rim," and it resulted from metal being forced through a gap between the perimeter of the die and the inside diameter of the collar. If all these pieces fit together perfectly, a complete seal was achieved, and no wire rim would be seen—at least not on coins struck for circulation. With proof pieces, however, the multiple strikes required to bring out the coin's design fully often produced a fine wire rim on one or both sides of the coin. On the proofs struck since 1968, especially those reeded-edge pieces made from the very hard copper-nickel-clad composition, these wire rims are sometimes sharp enough to cut a person's skin if the coin is not handled carefully.
David W. Lange's column USA Coin Album appears monthly in Numismatist, the official publication of the American Numismatic Association.